While animals including crows, chimps, dogs and dolphins are all highly trainable, you might think that the bumblebee, with its much smaller brain, wouldn't really get the hang of learning a new behavior from a trainer. However, in the words of a researcher from Queen Mary University of London (QMUL): "Our study puts the final nail in the coffin of the idea that small brains constrain insects to have limited behavioural flexibility and only simple learning abilities."
The study that professor Lars Chittka from QMUL's School of Biological and Chemical Sciences is referring to is one in which the bees were trained to roll a ball to a hole in the center of a field to score a treat. While bumblebees have previously shown the cognitive skills needed to do other simple tasks, those were mostly related to their natural behavior in the wild. In this case, the researchers wanted to see if they could teach the bees to do something out of their comfort zones.
"We wanted to explore the cognitive limits of bumblebees by testing whether they could use a non-natural object in a task likely never encountered before by any individual in the evolutionary history of bees," said Clint Perry, QMUL professor and joint lead author.
The bees were trained under three different conditions: they watched a previously trained bee roll the ball; they watched a ball roll that was being controlled by a magnet beneath the test bed's surface; or they simply found the ball in the hole at the outset. In all cases, a human tester opened a door beneath the hole to grant the bees access to a sucrose solution once the ball was in place.
The bees that were most successful were those that watched other bees complete the task. What's more, the new trainees were even able to improve on their predecessors' behavior.
In the first round of training, there were three balls placed on the field. The two closest to the goal were glued down however, so the bees were forced to move the ball farthest away to the central hole. Even when new bees watched this behavior, when given a field where all the balls could be moved, they chose to roll the closest ball into the hole, exerting less effort for their reward. In another test, they were able to adopt the trainer bees' behavior even when the ball color changed.
"The bees solved the task in a different way than what was demonstrated, suggesting that observer bees did not simply copy what they saw, but improved on it," said joint lead author Olli J. Loukola. "This shows an impressive amount of cognitive flexibility, especially for an insect."
The researchers hold that their experiments show an unprecedented learning ability in bumblebees. Their study has been published in the journal Nature. You can watch one industrious bee go to work in the video below.