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THOMAS D. SEELEY: Oh, yeah. And it's wonderful to be back in Mann Library presenting another one of these talks. I want to thank Mann Library more broadly because I've been using this place for, goodness knows, 38 years, when I was hired at Cornell.
But really, back when I was a high school kid, I could come in here. It was back in the day when it was a building. And you could get access to the whole stacks. You could browse every book in the library back then. It was really very special.
And I remember sitting in one of the desks up in the stacks and reading these books about bees. Was just starting to get interested and thinking, wow, this is really cool, and got book after book after book. So thank you very much to Mann. My thanks very much to Mann Library. Yeah.
Well, the title of my talk today, as you can see, is the title of this new book that I've written. And in the book I-- when I sat down to write this book, I realized I wanted to make it a different format than I had used before. It's a set of short stories, each one devoted to a particular investigation and description of a behavior of worker honeybees.
And so I made a list. And I think there were 35 topics on that list. And the editor at Princeton said, uh, no, 20 tops, Tom. And today, I can only do five. So I'm only going to skim a little bit of some of the cool stuff that we've learned over the years. Yeah.
And the title of the talk refers to two of those behaviors, piping bees. They're piping hot. They're warming up other bees. And boisterous buzz runners. They're activating other bees to launch into flight, as we shall see.
Here's the structure of my talk. It's going to have two parts. It's first going to be a look at the historical context of the investigations that I'll be presenting. You probably know that for thousands of years, humans have focused on what the workers in honeybee colonies provide.
And these have been very valuable things-- honey, beeswax, and pollination services. And much less attention has been provided to what the bees inside the hives are actually doing. And that's where I-- that's been my source of fascination.
So part two of this talk is a look at five of these mystery behaviors that the bees have been doing in their hives for, really, millions of years and have been solved about how they behave. And we're going to be looking at five communication skills.
Just to flesh out a little bit that initial assertion, the honeybee-- humans have been fascinated with honeybees for thousands of years. Yeah. And it goes way back before there's any archaeological records. But these are some of the earliest ones we have.
Cave painting in Spain, which depicts a person going up. Some look like vines to get high up to a nest of combs, of honeybees, to get the honey, of course. And then there's this nice drawing from the Nyuserre Temple, a temple of Nyuserre pharaoh of Egypt.
And here again, you see a beekeeper. In those long tubes are log clay pipes in which they housed their hives. They didn't have trees in Egypt. So that takes us back a few thousand years.
If we go back 400 years approximately, we'll see a nice drawing of a beekeeper. And that would have been in Switzerland. And Cosmographia was a Swiss predecessor to the Encyclopedia Britannica. Cornell Library has that. That's pretty cool. And so I pinched this drawing from it of a beekeeper tending bees in a skep.
And then 50 years ago, here's a drawing from my predecessor at Cornell, Roger Morse, which he purchased in a market in Kenya, where the beekeepers have hung up a log in a tree. And it wasn't to provide the bees necessarily with a cozy home, but was to get them into a place where they could get the honey easily.
So our original power of attraction to the bees was the delicious food, honey, that they produce. And these days, the bees are valued, of course, even more for their pollination services.
Here's a worker honeybee on an apple blossom. And here are 18 colonies that are parked up in a blueberry barren up in Maine. And correct me if I'm wrong, Scott, but I looked up-- on the internet, where else-- that the percentage of pollination services worldwide from honeybees are about 50%. And that means all of the other bees are doing the other 50%. So they're super important as well.
And there's a third way, besides being a source of honey and providing pollination services, that honeybees are important. They are a model system for studies of animal behavior. And what makes them a model system is we can go up to them.
We can get close. We can put them in what's called a glass-walled observation hive. We can see exactly what they're doing both outside the hive and when they're back at home, which is where, of course, most of their communications occur.
So I'm going to start by taking us to this gentleman here, who we see here on the left. This is Professor Karl von Frisch, photograph from about 1914. He was a professor at University of Munich for about 40 years.
And his initial investigations really weren't about behavior of the bees, per se. It was an early stage. He was one of the first people to actually do careful experiments of the sensory abilities of worker bees. And here he's doing an experiment.
On the left, we see him doing an experiment where he's testing their olfactory discrimination abilities. What he's done is he's trained bees or let bees collect sugar water on a piece of filter paper that had a certain scent. So they'd learn to associate that scent with the sugar water.
Then he'd give them this test with all those little boxes. And those little boxes have different scents in them. And only one has the scent to which they were presented with the food. And he could see how well they discriminate.
And if you look really closely under his hand, [INAUDIBLE] you see the little black spots. That was the box that had the trained scent to it. And that's where the bees are.
And then the other thing that he studied really closely was color vision. People had suspected honeybees have color vision because why else would the flowers produce all these beautiful colors? But it's one thing to think that. It's another thing to test it.
And the way he would test it is, again, he trained bees to come to a dish of sugar water on a piece of paper, colored paper about this size. And it was a little watch glass-- I guess that's what they're still called-- with the sugar water.
But it would just be one watch glass on one colored piece of paper. And then as the test, he put out this checkerboard array where there's that one square of the matching color, plus all these other squares of different shades of white, black, gray, et cetera, one of which, if they don't have color vision, they would confuse with the blue square.
And as you can see, he's got a little depiction here. The bees are all clustered around on this square here. So they know all about-- they're very sensitive to colors. Not red, but wavelengths shorter than reds.
Now, the stories I'm going to be telling about really picked up in 1945. This is the end of World War II, when von Frisch then was working with even simpler tools. And he discovered in that spring of that year that the worker honeybees can direct their hive-mates to rich food sources by giving them information about the direction and the distance.
And that is a real wow, because there's no other animal species except us that has that ability. And as I say, the wow is because what other animal-- and that's us. So I like the way human beings and honeybees are almost the same words.
So what we're going to look at is how worker honeybees do five things-- provide directions to important places, call for help-- help, help-- when unloading nectar, wake up their sleepy hive-mates, tell others to warm up their flight muscles-- that's in a specific context we will learn about-- and how they trigger an en masse takeoff of a swarm.
And if you don't know what a swarm is, it's a beard-like cluster of bees that hangs on a tree branch or something like that. It's a reproductive unit of a colony. A colony produces a swarm. It's about 10,000 worker bees that leave with the old queen.
They go out, they form a swarm cluster, and then they find a new home site. They're going to set up a new colony. So we'll be looking at how they organize the takeoff of a swarm. And these are five of the 20 solved mysteries of worker bee behavior that are discussed in my new book.
So behavior one-- and for each behavior, I've got a nice little video, so it won't be an abstraction-- provide directions to important places. You're going to see-- what you're going to be seeing here is a bee doing the waggle dance. She's dancing on the side of a swarm of bees, but it's the same waggle dance that they use to advertise food sources. Let's look at her.
Here she is. She waggles for a certain direction and a certain distance, comes around, waggles, comes around again, waggles. You can see other bees are tagging along behind her or beside her. That's pretty eye-catching. People had seen it for a long time, but nobody knew what it was.
Let's see. I had something in there. Guess not. And here's the way that information is coded in this dance. Imagine you've got a bee on the left panel over there. She's going out to flowers at a certain direction, from a certain location relative to her home in that bee tree, that tree there.
You can see in this example, those flowers are 40 degrees to the right of the direction of the sun at that time of day. And they have a certain distance from the tree, of course.
And what she can do when she does her dance is she can indicate the direction basically by copying that angle, memorizing that angle, 40 degrees to the right of her reference direction, the sun. And she does this dance inside the hive.
She can't see the sun, but she uses straight up as her reference direction. So she'll do this waggling motion 40 degrees to the right on a line, 40 degrees to the right of up. And she encodes the distance to the target, distance to the food source by adjusting the duration of the waggle run.
And that can vary from a second to several seconds. And her range of communication is out for thousands of meters. The longest dances I've seen are for dances representing food sources about six miles away. So that is 1.6 times 6. That's 9.6-- 3.6 miles, I guess. Yeah. Pretty far. Pretty far. Especially for-- it's a little-- it's an animal. It's pretty small.
And the way I like to think of this waggle dance is to think of it as a miniaturized reenactment of the flight to the food source because she's copying the same angle, only she's just shifted her reference direction. Up is now the reference. And she is doing this waggling motion, which is a little bit like the flight activity.
And again, I want to stress that these worker honeybees really get around. And this curve that I showed you before, you can see that it extends out to 5,000 meters or 3 miles. But as I said, it goes out to about 6 miles.
And just to emphasize, they really have to know. They have to be able to find their way around, which we won't talk about today, but is another subject, of course.
And as I said, Karl von Frisch decoded this dance in 1945. And then he eventually received the Nobel Prize for it in 1974 with a couple of other investigators of animal behavior.
And I liked the juxtaposition of these two photographs because it shows him as a young man, 1914, and about 70, 60 years later, 1974. This was taken in connection-- the one on the right is taken connection to the Nobel Prize.
And what I really like about it is, look at the tools he's using. He's still looking at bees with little feeder dishes. He was not known for being high tech. And it worked well for him. As you'll see, it worked pretty well for me too.
So that was behavior one, sharing information about the location of rich food sources. Behavior two is how a bee calls for help in unloading nectar. So this call for help is coming from a nectar forager.
Let's see. Yeah. Nectar forager there on the left, and a nectar store on the right. And you can see the difference in the size of the abdomens of those two bees. The nectar forager, her abdomen is swollen because it's bulging with nectar.
She has an organ in the abdomen called the crop or honey stomach. And she can basically double her body weight with nectar when she's out in the field and collecting it. So she comes back. She's met by the nectar store bee, who has a noticeably stubbier abdomen.
And the nectar store has her tongue out. And so the nectar forager slowly regurgitates the nectar that she's got in her honey stomach. And the nectar store receives it. And it's fun to watch this. I wish I had a movie of this, of how the abdomen gets smaller and smaller on the forager and bigger and bigger on the store.
But this is a very nice system. The unloading is done just inside the entrance of a nest or hive. And it means that the bees that are-- the foragers don't have to take time out to get rid of the nectar. They just pass it off and then go back to the flowers quickly.
But it creates a organizational problem. By having this division of labor, there has to be-- these two processes have to be kept in balance for the collecting cycle and the processing cycle. If the collecting gets ahead of the processing, there's going to be a bottleneck, and the nectar forager is going to be standing around.
And sometimes that happens. But that's where this next signal comes in. Yeah. Here's the problem. Rate of nectar collection varies greatly, and the problem they really have is when the nectar collection goes up, gets very high. And this-- yes, they need more of the receiver bees.
And this is very analogous to a problem that my dear wife, who's a Maine girl, has pointed out to me about sardine factories up along the coast of Maine. There the daily collection of herring was highly variable. So the factory was in a situation where some days they didn't need many workers. Some days they needed a lot of workers.
They didn't have a tremble dance, but they had a factory whistle. So they could sound the factory whistle, and folks who were in the town or nearby would come down to down the factory and cut up the herring to pack it into the sardine cans.
Sardine packers. I like that old photo. 1940, what's that? 84 years ago now. Yeah.
And honeybees, as I mentioned, also have a factory whistle. For them, it's not more sardine packers. It's more nectar stores.
And what is the bee's factory whistle? It is a behavior I'll show you now. It is this. It is this bee's behavior. Tremble dance. You can see why we call it the tremble dance. The bee walks around trembling.
And at first glance, you might think, that bee has suffered pesticide exposure or something. But no, it's actually a functional signal. You can see other bees turn to her, come up to her. They're actually listening and feeling her. And so that is a real symbol, a signal.
The German name is [GERMAN]. I guess that translates to tremble. I hope so. So that's our little tremble dancer.
And the tremble dance and the waggle dance work hand in hand. They're both done by nectar foragers. But a bee, a nectar forager, as is shown in this graph, whether she does a waggle dance or a tremble dance depends on how long she has to search to find an unloader in the hive.
You can see, if it's less than 20 seconds, she's going to have a high probability of doing a waggle dance. If it's longer, if it's longer than 60 seconds, then she has a high probability of doing the tremble dance.
And then there's an intermediate stage where she does neither signal because everything's just fine. The factory is in balance.
Now, historical note. Science is fun when-- it gets more interesting and fun as far as I can tell if I know the historical context of something. This tremble dance was first described back in the 1920s by Karl von Frisch.
And I've translated from his 1923 paper, which was actually one of his first real big papers on these dances. He wrote, "At times, one sees a strange behavior by bees who have returned home from a sugar water feeder or other goal. It's as if they had suddenly acquired the disease St. Vitus's dance." I think the more common name today is Huntington's disease.
That's what he wrote in 1923. Now we'll go jump ahead 40 years. 40 years later, he was still puzzled. And he wrote, "I think it tells the other bees nothing. And it's perhaps comparable to the condition that Florey has described as a neurosis." I like that.
And he also-- I was told by one of his students that around 1970, he said, I will give a prize to whoever finds out what the tremble dance, [GERMAN], means. So he didn't really believe what he wrote in 1965, apparently.
Alas, Karl von Frisch died in the summer of 1982, which was nine years before I performed this study that solved this 70-year-old mystery. And the solution to this mystery is that the tremble dance is a call for more of a colony's middle-aged bees to work as nectar receivers.
If we go back here-- yeah. If a bee comes in and gets unloaded quickly, nectar forager comes on, gets unloaded quickly, she recruits more bees to that, to her flower patch to collect more nectar. If she's over here, in a sense, she senses there's a problem. She does the tremble dance. And that calls for more of the middle-aged bees to take up the job of receiving nectar.
And I've shown this graph to engineers. And they say, amazing. This is a perfectly designed control system. Because it's got at one end of a variable, you do this. At the other end, you do this. And you've got this intermediate range where you don't do anything because the system won't jump back and forth between the two behaviors or activities. So go, natural selection.
So this brings us to behavior three, arouse sleepy hive mates. Here's a behavior that I sometimes wanted to be able to use in a lecture hall. I don't see anybody needing it today.
This is a behavior-- I'll show you a video of it, but the diagram alone indicates a lot of it. It's that bee sketched in black. She's grabbed another bee, got a good hold on her, and she's shaking her, shaking signal. Here's a video.
Grabs [INAUDIBLE] another bee. Please. There we go. One more, please. There we go. Now, I think you can imagine that if you were a bee and somebody comes along and grabs you and shakes you that vigorously, you're going to get a wakeup-- that's a wakeup call.
So why is this signal needed? Well, forager honeybees are not the bees that work inside the hive. Their activities, their work goes on around the clock. But foragers are in a situation where there's night and day, like we have.
And so they go to sleep at night. It's both restful, of course, and it helps them. And they do the same thing on days of poor weather. Saves energy.
And when I say they go to sleep, I don't mean that in-- I don't use the term "sleep" casually because there's a very precise set of criteria that identify whether an animal is asleep or not.
And the bees fulfill all of them, fill all of them. And these are sleeping bees. All four of these are sleeping bees. And the characteristics are, well, the bee is immobile. Her body hangs limply. You can see that very clearly here. This bee is immobile, not moving, just dangling from two of her legs.
Body hangs limply. Breathing slows. You might say, well, how do you know what the breath breathing rate of a bee is? They have abdominal pumping to move the air through their tracheae.
Body temperature drops. How do you measure a bee's temperature? With a thermal vision camera. You can't give them a thermometer. And the resistance to disturbance increases.
And how do sleep researchers of bees test resistance to disturbance? You poke the bee. If the bee is awake, she will go, what's going on? If she's asleep, no response. So sleep had been known by bees, though only in really about the past 15 years.
And this next signal, which I started to talk about, the shaking signal, is produced by successful foragers to wake up other foragers when they need to be woken up. And the message is wake up.
And I stumbled upon the clarification of the shaking signal because people had seen it, and they thought, yeah, it's got to be some sort of activational thing. But nobody had really found a clear context when it was done.
And I was lucky because I was doing some experiments up in the Adirondack State Park where there are no flowers. I go up there because I have real control over feeding stations being visited by bees.
And I'll take with me a colony living in a glass-walled observation. I'll train the bees out a couple hundred yards, meters out to a little feeding station. You can see-- that picture shows you a glimpse of the feeding station.
It's a Plexiglas plate with grooves machined into it. And on top of it, there's a little jar filled with sugar syrup. The bees can come up. They can put their tongue into the grooves, get a load of nectar, and go home.
Now, we were doing an experiment up there back in-- I forget what year. And there were three days. It was three days steady spell of rainy weather. Bees didn't leave the hive. And so things were very quiet in that colony.
On the morning of the fourth day, I said, well, OK, it looks like it's going to be good weather today. Let's give it a shot. I went out to the feeding station, loaded the feeder, and then I sat there and waited for the first bee to arrive.
The bee that's photographed here, red white, red thorax, white abdomen, was the first bee to visit my feeding station after these three days of rainy weather. And she loaded up as usual. And then she headed home.
And I remember calling on the walkie talkie, [? Susanna, ?] I bet she's going to do a really powerful waggle dance when she gets home, because it's good food. They haven't had food for a while. The nectar intake rate must be really low.
But then a couple of minutes later, I got a call back. Tom, she's not doing a waggle dance. She's walking around shaking lots of other bees. This looks very strange. And I said, oh, make a count of how many bees she shakes.
And let's just follow, see what she does. And what we learned on that morning is depicted here. On her first trip back, she walked around and shook looks like about 48 bees. Then she went back to the feeding station.
Next trip, she came out, shook 56 bees, et cetera, et cetera. She would come into the hive and do lots of shaking signals for really from-- I guess it was about 9 o'clock till about 10:30. And then she started mixing shaking signals with doing waggle dances. The white bar portion of the bar means she was doing waggle dances.
And then finally, she gave-- she stopped by noontime. It was just pure waggle dancing. So these two signals work together. If you come home and you need some help getting unloaded, you tremble once. If you don't, then you can do the waggling.
So that's why I call this signal the shake and wake signal. And we'll just play it again. I think you can sympathize. If you're a worker, you're a bee minding your business, sleeping, getting some good rest, and somebody comes along and grabs you by the bottom, the abdomen, you feel it. And you probably think, oh, OK, I'll wake up.
OK. That was behavior three. Moving right along. Behavior four, piping hot bees. Now, as you can see, piping is a signal produced by worker bees in a swarm. Well, a swarm, shown there, I like to call it a beard-like mass of about 10,000 worker bees and one queen bee.
It's formed when a colony gets very strong in the spring or early summer. And it divides itself. It fissions itself. And it sends forth a queen and about 70% of its worker bee force to create a daughter colony.
They don't make a straight shot from their old home to the new home because often they don't have that worked out at the time. They have to wait for good weather. And often, most of the time, the mass of departing bees will assemble into this beard-like mass hanging from a tree branch.
And about 500 of the bees in the swarm, a few percent, 5%, function as nest site scouts. And these are the bees that choose the new home site. So it's a very small fraction of the swarm. And they also organize the swarm's flight to the new home when they have finished making their decision-making.
And the process of the decision-making is a whole story in itself, so I won't go through that one. When these nest site scouts have finished choosing their new home, they begin to produce this signal called worker piping throughout the swarm. I'll play it-- show it to you now.
And what you're seeing here is these-- well, you'll be seeing bees are doing a piping. And they're piping this cage that's here because in my experiments with swarms, I like to put the queen inside a cage, so if the swarm flies someplace that's not appropriate, it won't go there all the way. It'll come back to the queen.
So these bees are worker bees in a swarm that's taken off. Their queen is still left behind. And they're piping. They're telling her, warm up and go.
And its message is, ladies-- in this case, lady, her majesty-- warm up your flight muscles. Get ready to launch into flight. This swarm is-- this piping signal is usually produced primarily when a swarm is-- when that massive beard-like mass of bees is preparing itself to launch into flight. But I can't video record it as easily as I did in this situation. So that's its message.
And to show you just how much warming a swarm has to accomplish, I show you these two thermal vision images taken about 15, 17 minutes before a swarm was launching into flight.
In order for a bee to fly, she has to have her flight muscles up to about 35 degrees Centigrade, 95 degrees Fahrenheit. But they don't keep their-- when they're just hanging in that cluster, they're not going to be-- it doesn't make sense for them to keep warming their flight muscles that's keeping them at that hot.
That would be like if you're parked in a-- if you're stuck in a traffic jam and you just let your engine run. They don't do that. They shut off the engine. Let the thorax get cool. So this is-- the top is an image. And you can see that 1:03 PM, which was 14 minutes before this swarm was going to launch into flight, the pipers were running around.
And you can see most of-- there was a little-- couple white dots, bees with white thoraces there. You can see those are the pipers. They're running around. And the surface [INAUDIBLE]. But most of the bees have thorax temperature of only 70 to 80 degrees Fahrenheit.
14 minutes later, there's been a lot of piping going on. Everybody's got a hot thorax. And then they launched into flight. So every bee has heeded the pipers and has warmed her flight muscles before a swarm takes to the air. That's a really important signal, too, isn't it?
Now, the last one, the one we started with in the cover image-- the boisterous buzz runners. This a four-panel display. Just gives you a little bit of a feeling. A bee is running, as the name implies. And while she's running, she's got her wings spread, and she's buzzing. Let me show you a video of this.
This bee is thinking-- or I don't know what it's thinking. But it's doing this because the queen is still there. So it senses that the queen needs to take off. So she's there doing her duty to try to get the queen to launch into flight. She does not know about-- that the queen is in a cage, obviously.
Its message is, time to go. Let's go. Oh, and here's-- turns out these buzz-- I didn't know who the buzz runners were until I really looked at this closely. It's the same scout bees. It's the bees that did the piping. And when these scout bees can sense that the mass of bees is warmed up, it's hot enough to take flight, then they shift into making the buzz run.
You can see that change in their distribution of behavior. 40 minutes, 35 to 40 minutes before takeoff, the percentage, the number of bees that were doing the piping, the gray part, is a small number. That number of pipers goes up and up. And as the pipers, after they've been going strong for a while, then the buzz runners kick in as the temperature has been reached for takeoff.
So just to summarize these five, I like to think of them as nifty signals of worker honeybees. The waggle dance is here's where to find forage. Tremble dance-- we need more nectar receivers.
Shaking signal-- shake and wake. Time to get up. Get going. Worker piping-- warm your flight muscles. Buzz run signal-- time to go.
Now, I want to stress. I've given you just a peek at the communication skills of worker bees. They possess at least seven more of these mechanical acoustical signals. And these include things like requests to be groomed, special flight behaviors to steer the swarm to its new home, the shaking of the queen, and still more.
And there are several of these that remain mysterious to me. There's one where the bee pipes, but instead of going "eee, eee" to the other bees, it's "eh, eh, eh." It's a short one. And I don't-- I haven't figured out-- you always have to find out what's the context in which that bees started making that signal. I don't know what that one is.
And then if we switch over away from mechanical acoustical signals and go to chemical signals, it gets even more tricky. They possess at least 10 known chemical signals and probably many more. And I think we only understand very well maybe a handful of those, maybe four.
And I want to conclude with this by quoting this distinguished English entomologist who had probably the world's best surname for being an entomologist, Wigglesworth. He wrote, "The honeybee is as far above the general run of other insects as man is above all his fellow mammals. The complexity of the social life of honeybees, their powers of mutual communication--" which is what we've been peeking at-- "their diversity and skills and employment, their debates and decisions on policy are so remarkable that they raise the question of the capacity of the worker bee for thinking."
And I agree. I think that's true. It's hard to imagine that an organism-- well, it could be possibly that the thing is just a bunch of hard-wired, sophisticated circuits that go from one to another.
But they're so flexible. They integrate so many things. I think it's more likely that they have some power of actually thinking about what they're doing, have some consciousness. It's not just a robot.
And I'll conclude with just another blurb about this or blab about this. To learn more about these, I recommend reading this new book. And like I say, it's only 20, but they're all 20 good stories. And they're all 20 mysteries solved. Thank you very much for your interest and attention.
[APPLAUSE]
SPEAKER: Thank you so much, Dr. Seeley. Do we have any questions in the audience?
THOMAS D. SEELEY: Yes.
BRYAN DANFORTH: I have two questions.
THOMAS D. SEELEY: Great. Thank you.
BRYAN DANFORTH: In my Alien Empire class, I tell students about the honeybee dance and everything.
THOMAS D. SEELEY: This is Bryan, Professor Bryan Danforth, entomology department, has written the world's book on the solitary bees
BRYAN DANFORTH: So I just-- I tell my students two things, and I want to know if this is correct. One of the anecdotes I tell them is that at the equator at noon, honeybees don't dance because there's no information from the sun. There's no directional information.
THOMAS D. SEELEY: No direc-- correct. So it's straight up. And it doesn't tell you, give you any directional reference.
BRYAN DANFORTH: So is it true? Do they stop dancing, or do they dance at random?
THOMAS D. SEELEY: They stop dancing. I guess that's more adaptive to-- rather than blab on. It's about 20 minutes before and 20 minutes after. Only need a few degrees of being off zenith to get directional information.
BRYAN DANFORTH: OK. And then the other thing I tell my students is that in the tropics, when there are night-flowering plants, honeybees will continue to dance, but they're indicating where the sun is, even though they can't see it. It's below the horizon. Is that correct?
THOMAS D. SEELEY: Yeah, that's also correct. Yes. And that's really important to some of the species. There's a species called Apis dorsata that forages in Asia. It's the giant honeybee. And most of its foraging is nocturnal. And so yeah, they are somehow-- and they're relating. They've learned the sun's course in relation to landmarks.
So even if they can't see the sun, they know that I go off in that direction towards that tree. And then apparently, they line up that tree with the next. I don't know how they get-- how they do it all the way to a source, but they are still orienting. They're still performing oriented waggle dances.
BRYAN DANFORTH: Thank you.
THOMAS D. SEELEY: Yeah. You're welcome. That's work by Fred Dyer at the University of Michigan.
AUDIENCE: And thanks. This was fascinating. So I teach in the communication department. And I teach a class on social networks and social capital. And I use-- I don't know which one of your books it was, but I used the example of the bees finding a nest as a kind of wisdom of crowds, that one--
THOMAS D. SEELEY: Bee democracy.
AUDIENCE: Yes. One bee goes out and says, this is a good spot, comes back. But another one has to corroborate it. It's not just that one bee gets to say-- so the question I have is it would suggest that they're imperfect. And some of them make errors, right?
They found a spot that the others didn't agree was a good spot. Is there some communication of error correction like, hey, last time you went out and you were wrong. We want you to know that you were wrong and not make that mistake again.
THOMAS D. SEELEY: No, we don't see anything like that. The bees have a self-correction technique. They go out to a place, and it's only mediocre, they won't do a strong dance for it. In fact, they will-- their interest in that site will decay quickly so that error doesn't keep getting propagated.
Whereas if they go to a humdinger of a site, they'll dance for it for a long time. And so it's an-- you've given a very interesting perspective. I wouldn't say they made an error. They've just come back with poor information. Right?
AUDIENCE: But some of them would be better than others, presumably, at making that judgment.
THOMAS D. SEELEY: I think they all are. As far as we they're all probably about the same in making that judgment. It's just that somebody found a cavity over here that wasn't-- the entrance or opening might have been too large. And the one over here found an entrance that was small and easily defended.
AUDIENCE: Right. Thank you.
THOMAS D. SEELEY: But no, that's a very thoughtful question you've asked to think about. Where does this poor information-- how do they deal with that? You're welcome. Thanks for the question. That's an interesting-- that's a question it's never been asked to me before. Yes.
AUDIENCE: I can shout out here.
SPEAKER: [INAUDIBLE]
AUDIENCE: In the natural situation, bees in a hive, dark tree, what you showed here is a lit-up dance where we all can see it. But then how does the bee in a hive perceive this dance that they don't see.
THOMAS D. SEELEY: Thank you for asking that question, because you're right on the mark. Their antennae are very sensitive. They can use their antennae. They can touch another bee, and they can feel whether that bee is buzzing, for example.
Or they can feel through their leg-- if the buzz runner, for example, is running over another bee, that buzzing vibration that the sender is making by buzzing her wings, that energy is going down into the bee she's walking on. And they feel that through their legs.
They've got-- let's see the best way to say it. They just have motion-- they have movement or vibration detectors in their legs. And so if they're getting vibrated and their legs are anchored to something, their body is getting vibrated, they will pick up that vibration.
So even if it's in the dark, that will happen. And even if it's in a swarm, it'll happen because they're standing more or less fixed on another bee. I don't know if I've answered the question.
AUDIENCE: Yes. [INAUDIBLE].
THOMAS D. SEELEY: Oh, OK. Yeah.
AUDIENCE: How do you-- I mean, that was sort of determined by the distance that the bee went in the hive or on top of the surface. So that's just one little section that the next bee over is aware of.
THOMAS D. SEELEY: Yeah. That's right. It's only-- yeah, you're getting it. I mean, you're thinking about it really carefully, closely. Yeah. The bees that are-- the only bees that will get the message from a waggle dancer are the bees that can put their antennae close to her and hear her, have those antennae vibrated so they can hear how long her waggle run is.
They can hear that waggling motion. And they're the ones that can feel the angle at which she's dancing. It is a remarkable thing. The bee is not-- if you had a waggle dancer that's dancing at 45 degrees to the right of vertical, that bee that's listening to her, she has to sense the angle of-- somehow she's able to sense the angle of that waggling run and then adjust and realize that that's 45 degrees from straight up, even though her body is nothing alike. It's not any of those directions.
It's why-- it's one of the-- put your finger on the things that keep us busy, in a sense of marvelous, marvel.
AUDIENCE: I think my question is kind of a follow-up on his that I kind of just thought about when I was listening to his question. I know bees have some degree of magnetoreception, and they can detect EMF frequencies like that. And I'm just wondering to what extent that's used in communication. And would that answer some of those questions of maybe without being right next to the bees or in contact with the bees being able to--
THOMAS D. SEELEY: Yeah, I'll have to-- here, I'm going to have to say that I have to admit my lack of understanding. The studies of bees responding to Earth's magnetic field are--
AUDIENCE: Really preliminary, right?
THOMAS D. SEELEY: Yeah. Preliminary is a good way to put it.
[INTERPOSING VOICES]
I'm not sure how much there is in those studies. There may be a great deal. I know they were done by one of Karl von Frisch's students. So I think they did it in-- with best of intentions.
But it involved putting bees while they were dancing in a Helmholtz coil. So you could manipulate the direction of the magnetic field.
AUDIENCE: I think I remember. Yeah.
THOMAS D. SEELEY: But I--
AUDIENCE: Yeah, I read a very little bit. I don't know if you read An Immense World, Ed Yong. And he-- I think it was him that talked about this a little bit. And I can't remember to what extent he talked about this being used in communication and things like the waggle dance and being able to tell others where to forage.
I'm wondering whether maybe something like that could answer some of the questions he was asking or bring some insight into that.
THOMAS D. SEELEY: It might.
AUDIENCE: It was interesting to think about.
THOMAS D. SEELEY: You pushed me to the edge of my knowledge of that.
AUDIENCE: I didn't know how much you knew. I just was wondering, OK.
THOMAS D. SEELEY: And that just hasn't been investigated very much either.
AUDIENCE: Thank you. We have an online question, which could go first. Yeah. I'll come back. It's a question from the online audience. Is there ever a situation when the forager will unload the nectar themselves, rather than pass it off to a receiving bee?
THOMAS D. SEELEY: I like that question. It's very exceptional. But yes, that happens. And sometimes I would be the person sitting by the observation hive. And sometimes occasionally, we would do experiments where we removed all the receiver bees to really-- to put the returning nectar foragers in a real bind and give them a real, real problem.
And yes, occasionally we did see some of those returning nectar foragers who couldn't find anybody who could take their nectar, just went to the cells and put it in themselves. And that probably was the ancestral condition. And then little by little, they worked out this division of labor to make it more efficient.
And the reason it's inefficient for a bee to just do it herself is because when a bee takes a load of nectar and she puts it in a cell, she takes time to smear it on the walls. So it has a large area for which to evaporate. And that takes time.
And so that's better done by this group of bees, rather than the bees that should go back outside and get to the flowers before the daylight ends or a rainstorm comes or whatever, things like that.
AUDIENCE: Hi. Thank you for this wonderful talk. I guess I've always been curious as to why bees swarm, because it seems like it puts them in a very vulnerable position, rather than why don't they just move out and move right into the next one?
And now I'm thinking, because they use the same communication signals in both cases for recruiting and moving into a new home and also recruiting foragers. So there's no way they could do it in the hive to pick out a new home?
THOMAS D. SEELEY: That would be one of the problems. You'd have some dances for food sources and have others for nest sites. I can only speculate, but I think this is right, that it's-- and nobody's really looked at this carefully. So this is really more speculation.
When a colony fissions itself, you see that almost all of the bees go out. And then some come back and repopulate the colony. It looks like they're doing some sort of adjustment process to get the right fraction gone and the right fraction staying.
And so it may be that's why they have to make this external grouping. Kind of like-- what's a human analogy where you-- base camp or something like that. And we know that they do a pretty good job of that.
We've measured the fraction of the worker bees that go in the swarm and the fraction that stay at home. It's about 70% go of the adult workers, 30% stay. And you might think, well, that's not many bees.
But you have to remember, there's going to be more bees emerging inside the home, the original home. And so the colony actually does repopulate itself pretty quickly.
AUDIENCE: You mentioned several physical behaviors, dances and the like, being ritualized or simplified forms of actions. Are there any acoustic behaviors where there's evidence that they're ritualized or simplified forms of natural sounds?
THOMAS D. SEELEY: Yeah. Thank you for asking that question because it helps me clarify something I said. When the bee's doing the waggle dance, she's doing some wing movements that she does-- not the ones where she has her wings spread for flight. But she's using her flight muscles to move the wings up and down.
And that makes a very nice-- that enables the bees that are near the dancer to hear the dance with their antennae. Because those air particles are going out and making little vortices right around her wings.
So yeah, you're right. That's really important. When she does the waggle dance, she's making the sounds with the wings. Thank you. What made you think about that? What was it--
AUDIENCE: Well, I was just-- I was wondering because with several of the initial ones where it clearly seemed more physical, the later ones seemed more acoustic, where it was more sound-based. So I was wondering, is there a generalized sound that would lead to this behavior later?
THOMAS D. SEELEY: And the reason I asked you why you thought about it is because whenever we show how the waggle dance works, we always present it like a visual problem. The bee can see the angle the bee is dancing. But no, she can't see it. She has to almost hear it, get the information through hearing. I think we've reached--
AUDIENCE: [AUDIO DROPPING]
THOMAS D. SEELEY: Bryan?
AUDIENCE: Let's do the online first.
THOMAS D. SEELEY: Oh. Online.
AUDIENCE: One more. We have one more online question. And that is what determines whether a bee is a collector bee versus a storage bee? Do they ever switch roles?
THOMAS D. SEELEY: Thank you for asking that question. What determines whether a bee is a nectar receiver or a nectar collector? It's about age. The nectar receiver bees-- well, I'll put it the other way. The nectar foragers are elderly bees. They're 20-plus days old. They're usually in the range of 20 to 30 days old.
The nectar receivers, the unloader bees, are in their age generally 10 to 20. They're the middle-aged bees. And so that's something that-- if they want to learn more, there's a whole chapter on that in this new book.
AUDIENCE: So do you care to speculate on why it's the older queen that leaves when the swarm leaves the colony? Wouldn't it make sense for the young queen to be the one that leaves? I don't know. I mean, it just seems kind of odd to me.
THOMAS D. SEELEY: It is odd. Except you have to realize that older queen is getting out of the killing fields, killing field. And because all those virgin queens are-- they're trying to kill each other off. And the mother queen, she'd probably be a so-called sitting queen. I mean, sitting duck, because she's bulky, maybe a little older. Her abdomen's long.
These young queens, Bryan, when they come out, they've got these stubby little abdomens. They can use their stings like stilettos. Just come up to another bee and stick it right in. So that's what they do. That's [INAUDIBLE].
That's what they're built to do, kill off their competitors. And if it's mom, they would probably do it to her too. I want this colony. This is a nice nest. Give it to me.
AUDIENCE: Do we have any last-minute questions? OK.
AUDIENCE: Currently taking the honeybees course here at Cornell. And during this semester, we've learned about this age-based task specialization that happens within the honeybee colony.
And so we've learned that the foraging, like you mentioned, it's the elderly bees. And then the younger bees are confined to tasks that mainly keep them within the hive. Why is it that this responsibility of going out into the world and foraging is reserved for the oldest of the bees?
Is it their cognitive abilities don't quite develop until near the end of their lifespan? Or is it some sort of other reason?
THOMAS D. SEELEY: Well, there's two parts to the answer to that question. One is at the mechanistic level, yes, there is some maturation of the nervous system that takes time. And part of that, a lot of it is about learning.
When you're a middle-aged bee, you can start going out of the hive and start making what are called [INAUDIBLE] flights, short flights. You can do the memorizing of what are the landmarks and the landmarks around your nest, and what the entrance of your nest looks like.
But I think the main reason-- and this is an ultimate reason-- is, again, the worker bee-- the logic is that natural selection has favored bees to postpone the outside work till the last stage of life, because that ensures that there's very little mortality of worker bees during the early stages of their life.
And thus the colony gets the best payback for producing a worker bee if it keeps the workers working inside as long as possible. And at the end of life, it goes out. They go out and do the dangerous work.
It's the opposite of the view of the military. They take the young men and women and put them in danger. So we do it backwards maybe. But who knows. I'll stop thinking about that.
At a Chats in the Stacks book talk presented at Mann Library in November 2024, Thomas D. Seeley, Horace White Professor Emeritus in Biology, discusses his new book "Piping-Hot Bees and Boisterous Buzz-Runners: 20 Mysteries of Honey Bee Behavior Solved" (Princeton University Press, 2024). Seeley, who has devoted nearly six decades to the study of honey bees and their colonies, takes us inside a world seldom seen even by beekeepers, to illuminate mysteries of honey bee behavior including how they choose a home for their colony, keep the colony inhabitants warm, and defended the colony from intruders. Weaving personal stories with the latest science, "Piping Hot Bees and Boisterous Buzz-Runners" shows both the excitement of scientific discovery and how it continues to shape our understanding of these vitally important insects. Dr. Seeley is Professor Emeritus of Biology at Cornell University. For 40 years, from 1980 to 2020, he taught courses on animal behavior and conducted research on the behavior, social life, and ecology of honeybees. His scientific work is represented in an extensive and distinguished publishing record, including a number of award-winning books about bee biology and behavior. Among other distinctions, Dr. Seeley has received the Alexander von Humboldt Distinguished U.S. Scientist Prize and has been elected a member of the American Academy of Arts and Sciences and the German National Academy of Sciences. Even longer than his career as a bee biologist, however, has been Dr. Seeley’s history as an avid beekeeper, having begun keeping bees when he was a high school student in the late 1960s, right here in Ithaca, New York. In his own words, while his professional distinctions have been gratifying, for Tom the most important ‘prizes’ by far are the discoveries that he has made about the lives of honeybees. For more Chats in the Stacks book talk videos, visit https://www.youtube.com/@mannlibrary and https://www.youtube.com/@cornelllibrary
