Emotion was once thought to be the realm of humans alone, but it increasingly appears that feelings are an evolutionary adaptation for all beings. Bees, it seems, have feelings too.
A new study published in Science on Sept. 30 compared the behavior of bees who received unexpected rewards to those who did not, and found the bees that were rewarded became optimistic—and that influenced the insects’ handling of new situations. Bees who weren’t rewarded appeared to respond less enthusiastically to new challenges.
The findings suggest that insects experience emotion and that their feelings have an adaptive role, functioning in insects, as they do in humans, to inform action. “We can’t say they experience life in the same way that we do,” Clint J. Perry, cognitive neuroethologist at Queen Mary University and one of the study’s co-authors, told Popular Science. “But on a basic level, there’s no reason to believe they can’t feel something. It does feel like something to be a bee or an ant or what-have-you.”
Perry and his colleagues tested bee feels with a series of exams. First, they gave the insects two choices and timed their decision-making process: entrance through a blue door led bees to plain water and entrance through a green door led to a sugary drink. The insects made their choices, either finding water or a sweet nectar. They were all then presented with a new choice: a bluish-green door.
The bees who had first chosen the green door that led them to sweet liquid, it turned out, were more quick to try the newest offering. They went through the mixed-hue door more determinedly than bees who had only found plain water on the first try. The insects who only found plain water before did not appear as intent on completing the next challenge.
The difference, the scientists say, can be attributed to a faster decision-making process informed by the reward. The bees that had been given the nectar weren’t just on a sugar rush—rather, they were less hesitant in their judgments based on a kind of optimism stemming from the combination of sugar and their experience. Another way to think about it: Bolstered by the benefit of a good experience, the optimistic bee seemed to face the unknown with greater confidence.
In another test, bees were trained to forage at a feeder that had a 30% sweet solution in it. Then, the bees were again released to forage at the feeder, with some getting a 60% sweet solution and some getting plain water. The bees were then trapped for 10 seconds with a simulated spider made of sponge—meant to strike fear into their bee-hearts that there was a predator on the loose. After being allowed to forage again, the insects who drank the high-sugar-concentrate were quicker to return to foraging post-predator encounter than bees who did not receive the sweet drink, suggesting that the sugary liquid influenced their resilience.
The scientists also figured out the underlying neuroscience behind the behavior: when scientists inhibited dopamine release in the bees’ brains, the positive effects of drinking sweet nectar were eliminated. That, the researchers say, is a sign the bees’ good feels are enhanced by the sweetness, which may indicate bees evolved to get positive feelings from the sugar they need to survive.