Play is common in many animals. House cats crouch down, focus, wiggle their butts, and jump on the rag mouse, then toss it up into the air and catch it once more. The dogs chase the ball, hold it in their jaws and return it to its owner with the intention of repeating the scene over and over again. They seem to never get tired. Meanwhile, they move their tails like a windshield in a clear demonstration of happiness. These object amusements have also been observed in other species, including crocodiles enjoying water jets or octopuses grabbing blocks in aquariums.
Now a team from Queen Mary University of London has identified bumblebees as the first insect that plays with objects. These bumblebees roll wooden balls repeatedly, seemingly just for fun, with no apparent incentive to do so. According to the authors in the journal ‘Animal Behavior’, this playful behavior is new evidence that bees can experience positive ’emotions’.
During the experiment, the researchers followed 45 bumblebees on a track and gave them the option of following an unobstructed path to reach a feeding area or diverting to an area with wooden balls. Each bee rolled the balls between one and, astonishingly, 117 times. The repeated behavior suggested that rolling the ball was rewarding. They were having a good time.
In a further experiment, 42 other bees had access to two color chambers, one always containing moving balls and one without any objects. When given a choice between the two chambers, neither of which contained balls, the bees showed a preference for the color of the chamber previously associated with the wooden balls.
No hunger or stress
The researchers say that the bees had no other purpose in moving the balls than the game. The activity did not contribute to survival strategies, such as obtaining food, cleaning up mess, or mating, and was performed under stress-free conditions.
In addition, the team found that younger individuals rolled more balls than older ones, mirroring the behavior of young children and other juvenile mammals and birds. In addition, the male bees rolled them for longer than the females.
The research builds on earlier experiments from the same lab on Queen Mary, which showed bumblebees can be taught to score a goal, by rolling a ball towards a target, in exchange for a sugary food reward. During the experiment above, the team observed that the bumblebees would roll balls out of the experiment, without getting any food rewards. The new research showed that the bees repeatedly rolled balls without having been trained and without receiving any food for doing so, it was voluntary and spontaneous, therefore similar to play behavior seen in other animals.
“It’s certainly mind-boggling, sometimes amusing, to see bumblebees display something resembling gameplay. They approach and manipulate these ‘toys’ over and over again,” said Samadi Galpayage, lead author of the study. “It shows, once again, that despite their small size and tiny brains, they are more than just little robotic beings. They may actually experience some kind of positive emotional state, albeit a rudimentary one, as other larger animals do.” and hopefully encourage us to respect and protect life on Earth more and more.”
“This research provides a strong indication that insect minds are much more sophisticated than we might imagine,” says Lars Chittka, professor of sensory and behavioral ecology, and director of the lab.
For the researcher, the study should serve to reflect on how we treat insects. He endorses “the need to do everything possible to protect insects a million miles away from the mindless, unfeeling creatures they are traditionally believed to be.”
training for life
Ignasi Bartomeus, a researcher at the EBD-CSIC at the Doñana Biological Station (Seville) and who did not participate in the study, believes that using “human concepts” to define the behavior of other species “is always complicated, but the researchers show how bumblebees’ behavior has many similarities to play. Moving balls is not an action that directly helps them survive. They initiate it spontaneously and even seek them out. Also, as in vertebrates, young individuals show more propensity to play.”
If so, what does this activity tell us about bees? For Bartomeus, the game “is important in many species to refine the motor apparatus and socialize in a safe environment. Despite not having a specific purpose, it constitutes training for real life. It is not surprising that many species of invertebrates also take advantage of the resources they have to develop game-like behaviors, although it’s hard to know what they feel or if they feel anything like us, as their brains work very differently.
The researcher points out that we have known for years that insects are more complex than we thought. In particular, bees have been shown to be able to memorize complex patterns, learn by observing other bees, and solve problems such as lifting a lid that blocks access to food. Also, your ability to take risks is modified by your previous experience. “It should not surprise us that behaviorally complex animals like bees, which build nests, forage on different flowers and fly across complex landscapes thousands of meters, require sophisticated behaviors, including types of play,” he says.