The study followed 45 bumble bees in an arena and gave them the options of walking through an unobstructed path to reach a feeding area or deviating from this path into the areas with wooden balls. Individual bees rolled balls between 1 and, impressively, 117 times over the experiment. The repeated behavior suggested that ball-rolling was rewarding. This was supported by a further experiment where another 42 bees were given access to two colored chambers, one always containing movable balls and one without any objects. When tested and given a choice between the two chambers, neither containing balls, bees showed a preference for the color of the chamber previously associated with the wooden balls. The set-up of the experiments removed any notion that the bees were moving the balls for any greater purpose other than play. Rolling balls did not contribute to survival strategies, such as gaining food, clearing clutter, or mating and was done under stress-free conditions. […] The new research showed the bees rolling balls repeatedly without being trained and without receiving any food for doing so — it was voluntary and spontaneous — therefore akin to play behavior as seen in other animals. Study first-author, Samadi Galpayage, Ph.D. student at Queen Mary University of London says that “it is certainly mind-blowing, at times amusing, to watch bumble bees show something like play. They approach and manipulate these ‘toys’ again and again. It goes to show, once more, that despite their little size and tiny brains, they are more than small robotic beings.”
“They may actually experience some kind of positive emotional states, even if rudimentary, like other larger fluffy, or not so fluffy, animals do. This sort of finding has implications to our understanding of sentience and welfare of insects and will, hopefully, encourage us to respect and protect life on Earth ever more.”