This is the best story I’ve come across in a long time: lab-kept bumble bees roll small wooden balls around, seemingly because it’s fun. If they can learn to play football, why not?
I have thought about how to explain it, but I think the summary by the authors themselves does it best:
We found that ball rolling (1) did not contribute to immediate survival strategies, (2) was intrinsically rewarding, (3) differed from functional behaviour in form, (4) was repeated but not stereotyped, and (5) was initiated under stress-free conditions.
Through the design of the experiment and with the support of behavioural observations, we excluded the possibilities that ball rolling was driven by exploration for food, clutter clearing or mating. Similar to vertebrate play, we also found age and sex differences for ball rolling by bumble bees: younger bees rolled more balls than older bees and male bees rolled individual balls for longer durations than females. We explicitly show that ball rolling is itself a rewarding activity.
After being trained to find freely movable balls in one of two differently coloured chambers, bees showed a preference for the colour of the chamber where they had rolled balls. Our results contribute to the question of sentience in insects and lend further support for the existence of positive affective states in these animals.https://doi.org/10.1016/j.anbehav.2022.08.013
In other words, play implies enjoyment and therefore the capacity to experience emotions. So we are going to have to think a bit harder about how we treat them.
There is also a question about whether wild bees would have the time to play. They live tough, short lives and it’s likely they don’t have that luxury.
But while we can find something positive and delightful, just watch the video over and over again: