Science reposts bumble bee play study

Science magazine resurfaced a 2022 bumble bee experiment on May 22, 2026, drawing fresh attention to a study that said bees rolled small wooden balls without any obvious practical purpose. The underlying paper, published in *Animal Behaviour* in October 2022, argued the behavior met established criteria for object play in animals. The researchers said the bees were not trained to perform the action and did not receive food for doing it. The repost spread widely on social media after Science highlighted the footage again for World Bee Day, according to the post and the original study. ### What did the 2022 experiment actually show? The *Animal Behaviour* paper reported that buff-tailed bumble bees, *Bombus terrestris*, repeatedly rolled wooden balls in controlled lab tests. The authors wrote that the behavior fulfilled behavioral criteria for play and resembled object play documented in other animals. Queen Mary University of London said on October 27, 2022, that researchers followed 45 bumble bees in an arena where the insects could either take a direct route to a feeding area or detour into sections containing wooden balls. (qmul.ac.uk) Individual bees rolled balls between 1 and 117 times during the experiments, the university said. ### Why did the researchers call it “play”? (sciencedirect.com) The researchers said the key point was the absence of an obvious reward or survival function. Queen Mary said rolling the balls did not help the bees obtain food, clear the arena, or find mates, and that the tests were conducted under stress-free conditions. Samadi Galpayage, the study’s first author and then a PhD student at Queen Mary, said in the university release that the bees approached and manipulated the “toys” repeatedly. (qmul.ac.uk) Galpayage said the observations suggested bees were “more than small robotic beings” and may experience positive emotional states, even if rudimentary. ### How did the team try to rule out simpler explanations? (qmul.ac.uk) A second experiment involved 42 bees and two colored chambers, Queen Mary said. One chamber consistently contained movable balls and the other contained no objects. When the bees were later given a choice between the two chambers without balls present, they preferred the color previously associated with the chamber that had contained the balls, according to the release. (qmul.ac.uk) The paper said that pattern supported the idea that interacting with the balls was itself rewarding. The authors also reported age and sex differences: younger bees rolled more balls than older bees, and male bees rolled them for longer than females. ### Was this the first time bees had been seen moving balls? Queen Mary said the 2022 work grew out of earlier experiments from the same lab in which bumble bees were trained to move a ball to a target in exchange for a sugary reward. (qmul.ac.uk) During those earlier tests, researchers observed bees rolling balls outside the task even when no reward was available, the university said. The 2022 study differed because the ball-rolling was described as spontaneous and voluntary rather than trained. That distinction is central to why the authors framed the behavior as play rather than task performance. ### Why is the repost circulating again now? Science magazine’s May 22, 2026 repost brought the study back into public view after first circulating in 2022. (qmul.ac.uk) The post highlighted the same core claim — that lab-kept bumble bees rolled wooden balls “for fun” — and social-media engagement accelerated again after the repost, according to the post referenced in the briefing. The original paper remains available through *Animal Behaviour*, and Queen Mary’s October 27, 2022 summary still includes the experiment details, video and comments from Galpayage. (qmul.ac.uk) (sciencedirect.com) (youtube.com)