For insects with such tiny brains, bees can be surprisingly clever. Aside from all their complex natural behaviors, research shows they're also fast learners. And in a new sign of what bee students can do, scientists have taught bumblebees to play golf.
Well, more like mini golf. The bees have yet to master driving, chipping or pitching, but they do show a remarkable ability to putt — albeit without using a putter. Still, for a bee, learning an apparently non-instinctive skill like rolling a ball into a hole takes "unprecedented cognitive flexibility," researchers write in the journal Science.
Previous studies have found that bumblebees can learn new skills, but those skills tend to resemble behaviors they already perform in the wild. A 2016 study, for example, taught bumblebees to access food by pulling on a string. That's impressive, but it's not without precedent for bees, which sometimes have to pull debris out of their nests or pull on flowers to reach the nectar inside.
And while rolling a ball into a hole isn't rocket science, it is a leap from the bees' normal behaviors — especially while walking backward, as some bees did in these experiments. It might even be totally new for them, says Clint Perry, a researcher at Queen Mary University of London (QMUL) who co-authored the study.
"We wanted to explore the cognitive limits of bumblebees," he says in a statement, "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."
Not only did they pass the test; they adapted and improved their new skills, hinting at mental abilities well beyond what most people would expect from a bee.
Bee the ball
The researchers first built a circular platform with a small central hole for sugar water — but that reward only became available when the ball was in the hole. They introduced bumblebees to this arena with the ball already in the hole, and after briefly exploring, each bee discovered the sugar water and drank it.
The team then moved the ball outside the hole and brought back some of the bees one at a time. The bees checked the hole and the ball for sugar water, and if a bee couldn't figure out what needed to happen, it received a demonstration: A researcher used a crude plastic bee on a stick to push the ball into the hole.
"Bees that saw this demonstration learned very quickly how to solve the task," Perry tells NPR. "They started rolling the ball into the center; they got better over time."
Next, the other bees were individually trained in one of three situations. One group entered the arena to find the ball outside the hole, then received a "ghost" demonstration in which a magnet hidden under the platform moved the ball into the hole as if by magic. The second group faced the same dilemma, but then watched the previously trained bees move the ball to the hole. The third group received no demonstration, finding the ball already in the hole with the reward.
When all these bees later returned to the arena, once again finding the ball out of place, their reactions varied based on how they'd been trained. Bees that saw a ghost demo performed better than the untrained control group, but neither learned the task as efficiently as those that had seen live or model demonstrators.
Ready to roll
The bees weren't just copycats, the study found — they could also modify their new skills. Researchers sent some bees into the arena with three balls at varying distances from the hole, and glued down the two closest ones, forcing the bees to roll the farthest ball. Those bees then trained other bees in the same scenario, but without any balls glued down. The teacher bees still rolled the farthest ball, thinking it was the only moveable one, so that's how the trainee bees learned the skill, too.
Yet when these trainees were later tested individually, they moved the closest ball instead of the farthest one, suggesting they'd learned the concept well enough to adapt it. And in another experiment, bees rolled a black ball into the hole even after being trained with a yellow ball, showing further flexibility.
"They don't just blindly copy the demonstrator; they can improve on what they learned," co-author and QMUL researcher Olli Loukola tells New Scientist. "This ability to copy others and improve upon what they observe, I think that's really important."
It's important partly because it could help bees adapt to upheaval in their habitats, like by learning to exploit new food sources when old ones vanish. And that kind of flexibility would be especially useful now, as many wild and domesticated bees are declining due to modern spikes in pesticide use, invasive parasites, habitat loss and human-induced climate change. That doesn't mean bees don't need help, but it does offer some hope the plucky pollinators still have a few tricks up their sleeves.
The study also says a lot about insect versatility in general, part of a growing scientific admiration for what their tiny brains can do. This is relevant not just to biologists and ecologists, but also to fields like robotics and artificial intelligence.
"Our study puts the final nail in the coffin of the idea that small brains constrain insects to have limited behavioral flexibility and only simple learning abilities," co-author and QMUL researcher Lars Chittka says in a statement.
The ball-rolling trick may even qualify as tool use, Loukola says, an ability typically associated with bigger, brainier animals like crows, elephants and primates. But regardless of whether it meets that standard, it does reveal a surprising degree of resourcefulness — and it begs the question of what else bees can do.
"It may be that bumblebees, along with many other animals, have the cognitive capabilities to solve such complex tasks," Loukola says, "but will only do so if environmental pressures are applied to necessitate such behaviors."