Bumblebees are associated with lives of work rather than play, but researchers have for the first time observed the insects playing with balls for enjoyment, just like humans and dogs.
A team of UK scientists watched bees interacting with inanimate objects as a form of play and said the findings added to growing evidence that their minds are more complex than previously imagined.
Lars Chittka, a professor of sensory and behavioural ecology at Queen Mary University of London (QMUL), said bees were “a million miles from the mindless, unfeeling creatures they are traditionally believed to be”.
She added: “There are lots of animals who play just for the purposes of enjoyment, but most examples come from young mammals and birds. This research provides a strong indication that insect minds are far more sophisticated than we might imagine.”
The findings, published in the journal Animal Behaviour, were based on a series of experiments where bumblebees were found to repeatedly roll balls when given the option, despite no apparent incentive to do so. Younger bees were found to roll more balls than older bees, while adult males rolled for longer than their female counterparts.
The researchers designed an experimental arena where 45 bumblebees were given the option of either walking through an unobstructed path to get a treat or going into areas with wooden balls.
According to the researchers, individual bees rolled balls between one and 117 times over the course of the experiment, and the repeated behaviour suggested ball rolling was rewarding, the team said.
In further tests, another 42 bees were given access to two coloured chambers, one of which contained wooden balls. When the balls were later removed, the bees showed a preference for the colour of the chamber previously associated with the balls, proving the bees were moving the balls for no greater purpose other than play, the experts said.
The scientists wrote in the paper: “We found that ball rolling did not contribute to immediate survival strategies [and] was intrinsically rewarding.”
Samadi Galpayage, a PhD student at QMUL, and first author on the study, said: “It is certainly mind-blowing, at times amusing, to watch bumblebees show something like play. It goes to show, once more, that despite their little size and tiny brains, they are more than small robotic beings.”
The latest study builds on previous research by Chittka, which showed that bumblebees can be taught to score a goal in exchange for a sugary food reward.
