Bee colonies are so much more than a hive of worker bees mindlessly going about their tasks as the queen bee looms overhead.
To an extent, they are their own complex organism. But they are also living societies, composed of individuals. Worker bees are not mere drones — rather, they have a stronger individual will than we might imagine.
In understanding these bees, we might just further our understanding of another other species — including ourselves.
Buzz Buzz — A new study published Monday in the Proceedings of the National Academy of Sciences reveals details of the complex social interactions among honey bees (Apis mellifera). The research hones in on trophallaxis, which includes not only food exchange between bees, but other forms of face-to-face communication.
The researchers studied how bees displayed individual behavior during social interactions, using certain benchmarks to determine bee individuality.
"We looked at measures of how frequently bees interacted," Nigel Goldenfeld, co-author on the study and Advanced Study Professor in Physics at the University of Illinois at Urbana-Champaign, tells Inverse.
To record these social interactions, the researchers first barcoded each bee. (Yes, just like you would for an item in the grocery store.) They then used high-resolution video cameras to capture footage of pairs of bees.
Bee interactions — like those observed among humans — seem to follow a pattern of heavy-tailed distribution, which suggests a considerable degree of variation in social interactions and individual behavior.
Goldenfeld explains heavy-tailed distribution like so: "If you measured the heights of students in a classroom, they might have an average of 5 feet plus or minus 3 inches, with most students within a few inches of the average. Heavy-tailed distributions do not have such an obvious average."
"If heights had a heavy-tailed distribution, you might have most students around 5 feet, some around 6 feet, a few around 7 feet, and an even smaller number around say 12 feet," he says.
"But this [distribution] happens for many quantities you can measure, such as people's wealth or income," Goldenfeld says. Or, as in this case, social interactions.
According to the researchers' analysis, some bees displayed higher degrees of food sharing and social interactions than others.
"Just like humans, some bees participate in more interactions than others," Goldenfeld says.
Just Like Us? — This connection proved too curious to resist for these researchers. After observing the honey bees, the scientists realized the findings could also apply to humans. So, the scientists compared the two species.
"Bees are social insects, and it is relatively easy to study large populations of bees, perform multiple replicates of the experiments, and thus get precise statistics," Goldenfeld says. "Only after we had obtained our results did we compare with humans, really just out of curiosity."
To do this, Goldenfeld and his colleagues used the Gini coefficient — a measure normally used to determine income inequality, but which can also measure inequality among social interactions — to measure differences in individuals' behavior among both bees and humans.
"For humans, you might measure this by how many times they meet someone for coffee every week. For bees, you can measure this by how many other bees they interact within a certain time," Goldenfeld says.
They found that honey bees have a Gini coefficient in the range of 0.2 to 0.3, which means there is a fair degree of individual behavior in bee social interactions.
In comparing the bees to humans, the scientists found that some bees — like some humans — interact more and for longer periods, making them more social than their peers.
"It really jumped out at us that the data looked the same," Goldenfeld says.
It is important to note the similarities have a limit. The bees in this study did not display as much variation in social interactions as humans, who had a higher Gini coefficient in the 0.3 to 0.5 range.
"Thus, although individual bees are distinct, they are not as different from each other as humans are," the study authors say.
But the results seen here might look quite different in a more genetically diverse bee population. And the researchers believe the findings ultimately apply to other social species, including humans.
"The fact that we discovered these commonalities and could explain them theoretically is important for human interactions," Goldenfeld says. "It means that we do not need to try and explain universal behavior using ideas and behavioral models that are specifically dependent on the special features of human societies."
Abstract: The duration of interaction events in a society is a fundamental measure of its collective nature and potentially reflects variability in individual behavior. Here we performed a high-throughput measurement of trophallaxis and face-to-face event durations experienced by a colony of honeybees over their entire lifetimes. The interaction time distribution is heavy-tailed, as previously reported for human face-to-face interactions. We developed a theory of pair interactions that takes into account individual variability and predicts the scaling behavior for both bee and extant human datasets. The individual variability of worker honeybees was nonzero but less than that of humans, possibly reflecting their greater genetic relatedness. Our work shows how individual differences can lead to universal patterns of behavior that transcend species and specific mechanisms for social interactions.