Bumblebees Like Playing With Toys, Study Finds

It’s a little like bumblebee gymnastics with maybe a bit of logrolling thrown in.

A new study finds that bumblebees like to play. They like to roll around small wooden balls with no apparent motivation other than it likely makes them feel good.

“As humans, we might believe that we are the smartest and perhaps the only creatures in the animal queendom capable of having feelings and subjective experience, but is this really the case?” study first-author Samadi Galpayage, a Ph.D. student at the Queen Mary University of London, tells Treehugger.

“Through bees, I can learn more about how an animal very different from humans may experience the world. Bees are an excellent model system to study cognition: They are very efficient learners and show flexibility in their problem-solving abilities.”

Recent evidence suggests that bees have positive and negative emotion-like states. Usually, in studies, bees are given food rewards to test their abilities.

Instead, in this new experiment, bees were presented with small balls and got no reward when they repeatedly interacted with them, hopping on top and pushing them.

“The behavior was voluntary and spontaneous,” says Galpayage. “Bees have a reputation of being hard workers, which they are, but the prospect of bees engaging in something like play is certainly novel and exciting because it shows that bees may experience pleasure and don't only carry out duties that are strictly essential for immediate survival, such as foraging.”

Studying Bees and Balls

In an earlier study, other researchers had trained bumblebees to roll balls into a target in exchange for a sweet treat. They noticed that sometimes bees would roll the balls outside of the experiment area for no reward.

“This observation gave rise to new questions: What are they doing? Why? Is this random or repeated? Which bees do this?” says Galpayage. “Since there was no incentive to roll these balls, as bees were not getting any food for doing so, the observation provided a testable hypothesis of whether this phenomenon was something like play.”

For their recent study, researchers set up a number of experiments. They watched 45 bumblebees in an enclosed arena where they could walk through a clear path to reach a feeding area, or they could go off the path into areas with wooden balls.

They found the bumblebees went out of their way to interact with the balls. Each rolled the balls between one and 117 times during the experiment. The researchers say that because they did it repeatedly with no food payoff, that suggests that the ball rolling was rewarding.

In another experiment, 42 bees were able to enter two colored chambers, one that always had balls and the other with no objects. When offered a choice later between the two chambers without balls, the bees preferred the chamber that was the same color as the earlier one that contained balls.

In all experiments, rolling balls didn't gain them food, clear clutter, or help with mating. There was no purpose to moving the balls other than play.

The results were published in the journal Animal Behaviour.

Defining 'Play'

To define the ball rolling as “play,” researchers relied on a framework that uses five criteria to fit that definition. This included that the behavior didn’t contribute to survival strategies, started during stress-free conditions, and was intrinsically rewarding.

“Mainly, we found that bees engaged in the ball rolling activity repeatedly despite the absence of an external incentive, such as getting food/mates/shelter. Rather, the behavior was rewarding in itself, which is what play is,” Galpayage says.

They also found that the patterns of play in relation to age resembled other young mammals. Younger bees engaged with the balls more than older bees, and male bees rolled balls for longer periods than females.

“That bees may play is an important finding for science because it provides further evidence that an insect may experience something like pleasure,” says Galpayage. “Personally, I find this behavior fascinating because it tells us that bees, like many other animals, are more than little robotic beings, but have a richer behavior and life than we would have previously thought.”