Bumblebees Show Spontaneous Problem-Solving Skills

Despite having tiny brains, bumblebees have demonstrated a remarkable ability to socially learn how to use tools, solve simple puzzles, and cooperate to achieve a goal. It seems they can also solve object-manipulation tasks without any previous training, according to a new paper published in the journal Science.

According to the authors, it’s the first time this kind of spontaneous problem-solving has been demonstrated in an insect.

In 2024, Olli Loukola of the University of Finland co-authored a study demonstrating that bumblebees could cooperate to solve complex challenges. It’s the kind of cognitive task scientists had previously only observed in large-brained mammals like humans and chimpanzees. Loukola et al. trained pairs of bees to push a Lego block to the middle of a mini-arena or push against a door at the end of a tunnel to get a reward.

The team noticed that the bees were more likely to engage in the tasks if their partners also participated, compared to untrained control groups. They concluded that bees can learn to solve novel cooperative tasks outside the hive and may even be intentionally working together, although the researchers cautioned that more detailed monitoring of the behavior was needed to fully understand the partners’ roles.

For this latest study, Loukola was interested in whether bees could spontaneously solve problems. The first experiment featured an artificial flower placed above a pit in the floor so that there was insufficient space for a bee to hover to reach the flower. The bee would have to roll a small ball into the pit and climb on top to reach the flower. “This is essentially an insect version of the classic ‘box-and-banana’ problem,” said Loukola. “The animal must realize that an object can be repositioned and then used as a tool to reach an otherwise inaccessible goal.”

One set of bees was trained to recognize the flower as a source of sugary reward and that the ball could be moved into the pit, but they were not trained to solve the experimental conundrum. “They only learned the properties of the individual elements and success would therefore reflect spontaneous problem-solving rather than gradual reinforcement learning,” the authors wrote. A second group was trained that the flower was a source of reward but not that the ball was movable. And a third group received no training at all.

Bees in the first group solved the problem at a much higher rate than those in the other two groups, whose poorer performances were similar. The first group also made more attempts at working the problem, and the bees interacted with the ball more efficiently and in a more structured way than those in the other two groups.

To bee or not to bee

Those initial results were interesting, but Loukola et al. wanted to rule out the possibility that bees might have an inherent preference for rolling balls, such that perceptual feedback may influence their actions, i.e., rolling the ball might be rewarding on its own. So the team performed a second version of the experiment in which a barrier with a small opening blocked the bees’ view of the flower. The bees had to roll the ball through the opening to climb on top and reach the flower.

“This design assessed whether bees could solve the task without continuous perceptual feedback,” the authors wrote. All told, 16 of 22 bees succeed in this task. Granted, the bees could still potentially catch a glimpse of the flower once the ball was near the opening, so the team repeated the experiment with three openings in the barrier to further limit visual feedback. This time, there were no significant differences in performance between trained and untrained (control group) bees.

In one last experiment, Loukola et al. sought to isolate the bees’ goal-directed performance from accidental success and from visual feedback cues. This time, the testing apparatus featured a rectangular arena with two compartments, both invisible to the bees. During pretraining, 30 bees were shown the flower positioned above one of those compartments. For the actual test, the flower was not visible from the ball’s starting location, and the bees had to move the ball into the correct compartment. The results: 23 of the 30 bees succeeded at the task, and 16 of the successful 23 bees did so without first moving the ball to the incorrect compartment.

The team acknowledged that the experimental setups had no way to track the bees’ gaze, posture, or other behavioral cues that might have let them pinpoint the precise “Eureka!” moment when the bees “understood” the problem. Further experiments should test how well bees grasp causal relationships. “Nonetheless, the present design provides the clearest evidence to date that bumblebees are capable of generating novel, goal-directed solutions, establishing a foundation for future studies to further investigate the cognitive processes underlying insight in insects,” the authors concluded.

Science, 2026. DOI: 10.1126/science.ady1618 (About DOIs).