Entice them with a sweet reward and bumblebees can be trained to roll a ball into a goal, revealing unexpectedly complex learning abilities for an insect, researchers said Thursday.
The findings in the US journal Science offer the first evidence that bees can learn a skill that is not directly related to their typical duties of foraging for food.
Even more, bumblebees appeared to learn best by watching the behaviour of other bees, and sometimes even improved on their predecessors' techniques.
Until now, the ability to learn how to solve a complex problem by reaching a goal was known to be possible in humans, primates, marine mammals and birds. But insects were not necessarily considered part of this elite group.
"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," said co-author Lars Chittka, a professor at Queen Mary University of London's School of Biological and Chemical Sciences.
Previous studies have shown bees could learn to pull on a string to get a food reward and perform other simple tricks, but these studies were limited in scope because the "learning processes involved might be used in tasks encountered by bees naturally," said the study.
Researchers wanted to explore whether or not bees could learn to manipulate an object -- in this case a small, yellow ball - unlike anything they knew in their daily lives.
"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 joint lead author Clint Perry, also of the QMUL School of Biological and Chemical Sciences.
The bees were trained, one at a time, to roll the ball, which was about the same size as the bees themselves.
The ball had to be pushed to a specific target before a sugar solution would be awarded to the bee.
Some bees were trained by observing a bee that had already learned the technique.
Others were shown how by a hidden magnet beneath the platform which moved the ball. A third group received no instructions at all.
The bees learned most efficiently from watching other bees, it turned out.
Sometimes, they even found better ways to get a treat, for instance by choosing one of a selection of balls that was already closer to the goal than the others, instead of picking the ball that was furthest away as the trainer bees consistently did.
"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 Loukola.
"This shows an impressive amount of cognitive flexibility, especially for an insect." But don't expect that bumblebee buzzing in your garden to be ready to join your football team just yet.
"It may be that bumblebees, along with many other animals, have the cognitive capabilities to solve such complex tasks, but will only do so if environmental pressures are applied to necessitate such behaviours," Loukola said.