In a new study, bumble bees solve a completely novel object-manipulation task. What makes this behavior especially remarkable is that the bees had never been trained. The findings challenge the long-standing assumption that spontaneous problem-solving is restricted to humans and other large-brained vertebrates.
More than 100 years ago, psychologist Wolfgang Köhler famously showed that chimpanzees could solve novel problems by suddenly combining objects in new ways, such as stacking boxes to reach an out-of-reach banana. These experiments became some of the earliest and most influential demonstrations of insight and spontaneous problem-solving in animals.
Now, researchers from the University of Oulu, the University of Helsinki, and the University of Turku in Finland report strikingly similar problem-solving abilities in bumble bees.
In a study published in Science, bumble bees (Bombus terrestris) solve a completely novel object-manipulation task without being trained on the solution itself. The bees first learned that a blue artificial flower signaled reward.
During the test, the flower was moved to the ceiling of a transparent arena, out of reach. To access it, the bees had to spontaneously generate a novel solution by moving a ball underneath the flower and climbing onto it, a behavioral sequence they had never previously encountered or been trained to perform.
"This is essentially an insect version of the classic 'box-and-banana' problem," says senior author Olli Loukola, Docent at the University of Oulu. "The animal must realize that an object can be repositioned and then used as a tool to reach an otherwise inaccessible goal. What stands out about the result is that this kind of spontaneous problem-solving is now demonstrated in an insect."
"What makes this behavior especially remarkable is that the bees had never been trained to roll the ball. This was a completely new challenge. Their behavior appeared goal-directed, with successful individuals showing more directed movement patterns," says lead author Akshaye Bhambore from the University of Oulu.
Several control experiments to rule out simple explanations
The bees were not trained to move the ball underneath the flower. Instead, they only learned two separate pieces of information beforehand: that the blue artificial flower contained a reward, and that the ball was a movable, non-threatening object.
When tested in a completely new situation, many bees used their prior experience with the flower and the movable ball in a way that went beyond the behaviors they had been trained to perform.
"Another important aspect is that our bees were fully naïve," Loukola adds. "In many previous studies of insight-like problem-solving, the animals have had extensive experience with objects, test environments, or other problem-solving tasks. Here, the bees had never been trained to use the ball to reach the flower, and they had no previous experience with this kind of solution.
"We also designed the experiments to rule out simpler explanations such as accidental success, play behavior, trial-and-error learning, or direct visual guidance."
Importantly, the researchers designed several control experiments to rule out simpler explanations based on accidental solve or direct visual guidance.
In the more demanding tasks, the flower was hidden from the bees while they moved the ball, preventing them from simply steering toward a visible target. Even under these conditions, bees successfully moved the ball to the correct location.
"By analyzing the bees' behavior across unusually stringent control experiments, we could show that they were not simply reacting to visual stimuli or moving the ball randomly," says lead author Bhambore.
Watching the experiments unfold was often surprising even to researchers
"One moment the animal is exploring seemingly without direction, and the next it performs a highly efficient sequence of actions leading directly to the solution," says co-author Ece Nur Akmeşe from the University of Helsinki. "Watching the bees solving the task was genuinely fascinating."
The study builds on growing evidence that bees possess surprisingly sophisticated cognitive abilities despite their tiny brains. Previous research has shown that bees can socially learn tool use, solve puzzle-like tasks, cooperate with one another, and flexibly adapt their behavior.
However, the researchers emphasize that the findings do not imply human-like reasoning or consciousness in insects.
"We are not claiming that bees think like humans," says Loukola, who currently works as a Senior Researcher at the University of Turku. "But our findings show that miniature brains can generate flexible solutions to novel problems in ways we are only beginning to understand."
The results suggest that spontaneous, goal-directed problem-solving can emerge in animals with brains vastly smaller than those of vertebrates traditionally studied in insight research.
"For over a century, spontaneous object-based problem-solving has mostly been studied in vertebrates," says Loukola. "Our study suggests insects may belong in that conversation too."
Publication details
Akshaye A. Bhambore et al, Spontaneous problem-solving in bumble bees, Science (2026). DOI: 10.1126/science.ady1618. www.science.org/doi/10.1126/science.ady1618
Journal information: Science