Bumblebees are capable of solving a simple puzzle box to get a reward—and they can even learn the behavior from other bees, researchers reported Tuesday in the journal PLOS Biology.
Though people might not realize it, insects display a number of complex behaviors, such as building sophisticated nests and dividing labor within colonies. “[Bumblebees] have some of the most intricate, complex behavioral repertoires in the animal kingdom. Yet people assume that they’re mostly driven by innate factors,” Alice Bridges, first author of the new study and a behavioral ecologist at Anglia Ruskin University in England, tells NPR’s Ari Daniel.
In the new study, researchers designed petri dish-like puzzle boxes that bees could open either by pushing a red tab clockwise or a blue tab counter-clockwise. Inside, the boxes contained a sugary treat. The researchers trained a few select buff-tailed bumblebees to open the box using just one of the colored tabs—some were taught to use the red tab, and the others were taught to use the blue one. Scientists then placed a trained bee, called a “demonstrator,” along with additional puzzle boxes, into each of ten colonies.
The colonies that were introduced to a red tab-pushing bee predominantly used the red tab to get at the sugar, while colonies with a blue tab expert mostly used the blue tab. In fact, the bees used the same tab as the demonstrator 98.6 percent of the time, on average.
While some bees did discover that they could open the box just as well by using the other tab, that strategy didn’t last. “Even when they found the easy alternative, they still flipped back to the demonstrated behavior,” Bridges tells New Scientist’s Sofia Quaglia. “That was really crazy.”
The researchers also observed control groups of bees that weren’t placed with an observer. While some of these bees did learn how to open the boxes on their own, they didn’t do so as frequently as the bees that had someone to learn from. “Most did it only a handful of times and then never again,” Bridges tells Scientific American’s Rachel Nuwer. “So having the social learning element was critical to get the bees to actually permanently add box opening to their behavioral repertoire.”
The results of the experiments suggest that the bees learned how to open the boxes from each other. “We were taught that a lot of insect behavior was kind of hardwired,” Jessica Ware, an entomologist at the American Museum of Natural History who didn’t contribute to the study, tells NPR. “And what this paper does is kind of turn that on its head. I mean, who knows what grasshoppers are capable of doing—or the lowly cockroach.”
In previous studies, scientists have demonstrated that other animals are able to learn from each other. Honeybees learn a dance to communicate where pollen and nectar can be found. Chimpanzees and great tits, in different experiments, were trained to discover food hidden in human-designed structures, and others of their species later learned the foraging strategy from them.
Behaviors that are learned from others and shared in a group are a basic example of culture, writes Scientific American. The “exciting and groundbreaking study” takes the evidence of culture’s prevalence among animals “to new levels,” Andrew Whiten, a cognitive ethologist at the University of St Andrews in Scotland who didn’t participate in the research, tells the publication.
Some experts aren’t so eager to conclude that bees have a culture, however. While they did seem to transmit information such as the need to push a lever and which lever to push, the insects did not prove that they could share a series of actions, Claudio Tennie, a cognitive archaeologist at the University of Tübingen in Germany who was not involved in the study, tells New Scientist. “I label these things as minimal culture,” he says to the publication.