Bumble bees play with rolling wooden balls which demonstrates for the first time that insects are able to have fun.
The new study indicates that bees have minds that are more complex than previously believed. findings added to growing evidence that their minds are more complex than previously imagined.
A variety of animals have been found to interact with and manipulate inanimate objects ‘just for fun’, that is, to play.
Most clear examples of object play come from mammals and birds. However, whether insects interact with inanimate objects as a form of play has never been systematically examined.
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 scientists found that ball rolling did not contribute to immediate survival strategies and it was intrinsically rewarding. The bees weren’t under stress while rolling the ball, so the researchers could dismiss that the behaviour was done because they were under duress.
“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,” said the study authors in the journal Animal Behaviour.
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.
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.
Play is not limited to humans, but is a phenomenon seen across many animal species. It is thought to contribute to the healthy development and maintenance of an animal’s cognitive and motor abilities, which may, for example, benefit foraging strategies, and is considered an important aspect of animal welfare.