Bumblebees play, according to new research published in the journal animal behavior. This is the first time that object-playing behavior has been shown in an insect, adding to mounting evidence that bees may be feeling positive “emotions”.
Several experiments have been carried out by a team of researchers, led by scientists from Queen Mary University of London, to test their hypothesis. They showed that bumblebees went out of their way to roll wooden balls repeatedly despite no apparent incentive to do so.
According to the results, younger bees roll more balls than older bees. These results reflected the human behavior of young children and other young mammals and birds being the most playful. In addition, male bees rolled balls longer than their female counterparts.
Forty-five bumblebees were followed in the study as they passed through an arena. They were given the option of walking through an obstacle-free path to reach the feeding area or deviating from this path to areas with wooden balls. Individual bees rotated the balls an impressive between 1 and 117 times during the experiment. The repetitive behavior indicates that rolling the ball was rewarding.
This was supported by another experiment in which a different group of 42 bees were given access to two colored rooms. One room always contains moving balls, while the other room does not contain any objects. When subsequently tested and given a choice between the two chambers, as neither of them had balls at the time, the bees showed a preference for the room color previously associated with wooden balls. The setup of the experiments removed any notion that the bees were moving the balls for any purpose other than play. Rolling balls did not contribute to survival strategies, such as obtaining food, de-cluttering, or mating, and this was done under stress-free conditions.
The study expands on previous work from the same Queen Mary lab that showed bumblebees can be trained to score goals by rolling balls to goals in exchange for a sugary food reward. During the previous experiment, the team noticed that bumblebees rolled balls out of the experiment, without getting any food reward. The new research showed that bees repeatedly roll balls without being trained and without receiving any food to do so – this was both voluntary and spontaneous – and thus similar to play behavior as seen in other animals.
Samadi Galpayage, first author of the study and a doctoral student at Queen Mary University of London, said: “It is certainly amazing, sometimes even fun, to watch bumblebees display something like toys. They approach and manipulate these ‘toys’ over and over again. It shows, once and for all. Another, that although their brains are small, they are more than just small robotic beings. They may in fact experience some kind of positive emotional states, even if primitive, like other large animals that are thin or not very thin. This kind of discovery has implications. On our understanding of insect consciousness and well-being, we hope it will encourage us to respect and protect life on Earth more than ever.”
Professor Lars Chitka, Professor of Sensory and Behavioral Ecology at Queen Mary University of London, head of the laboratory and author of the recent book The Bee Brain, said: “This research provides a strong indication that insect brains are much more sophisticated than we might imagine. There are a lot of animals out there. that play just for fun, but most examples come from small mammals and birds.
“We are producing ever-increasing amounts of evidence supporting the need to do everything we can to protect insects a million miles away from the reckless, emotionless creatures traditionally believed to be.”
Reference: “Do bumblebees play?” By Hironi Samadi Galbage Donna, Quinn Solvey, Amelia Kowalewska, Carly McKella, Hadi Mabodi, and Lars Schitka, October 19, 2022, animal behavior.
DOI: 10.1016 / j.anbehav.2022.08.013