What do you think of this fact?
Dogs chase balls. Kittens bat at yarn. Bumblebees? They roll balls too, and nobody pays them for it.
The detour nobody needed
Researchers from Queen Mary University of London and the University of Oulu in Finland built an arena for 45 bumblebees. The bees could take a clear path straight to a feeding area, or they could make a detour into areas with small wooden balls.
And they did take that detour: individual bees rolled balls between 1 and 117 times. There was no sugar reward and no training involved, and according to CBC the bees had unlimited sugar solution and pollen anyway.
Do bees actually enjoy it?
To find out, the team ran a second experiment with 42 different bees. They had access to two chambers in different colors: one with movable balls, one with no objects at all. Later, the bees got to choose between two chambers of those colors, this time both without balls. They preferred the color they had linked to the balls. That suggests rolling them felt rewarding.
A few more details make it look a lot like play. Younger bees rolled more balls than older ones, and males rolled them for longer than females. The rolling didn’t help the bees get food, clear clutter or find a mate, and it happened under stress-free conditions. The study appeared in 2022 in the journal Animal Behaviour under the title “Do bumble bees play?”.
Lars Chittka from Queen Mary University of London summed it up: “This research provides a strong indication that insect minds are far more sophisticated than we might imagine.”
Bonus fact: The idea came from an earlier experiment in which bees were trained to roll a ball to a target for a sugar reward. During that work, some bees rolled balls even when there was no reward at all.
Busy as a bee? Apparently even bees make time for a little ball game.