Bumblebees can spontaneously solve problems, study finds
Source: Ars Technica
Making a Beeline
Scientists in Finland found bees could solve an insect version of the classic “box‑and‑banana” problem.
Credit: Mikko Törmänen
Introduction
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.
A new paper published in Science shows that they can also solve object‑manipulation tasks without any prior training, marking the first demonstration of spontaneous problem‑solving in an insect. [Science paper]
Background
In 2024, Olli Loukola (University of Finland) co‑authored a study that showed bumblebees could cooperate to solve complex challenges—tasks previously observed only in large‑brained mammals such as humans and chimpanzees.
- Pairs of bees were trained to push a LEGO block to the centre of a mini‑arena or to push against a door at the end of a tunnel to obtain a reward.
- Bees were more likely to engage when their partners also participated, suggesting intentional cooperation, though the authors note that more detailed behavioural monitoring is needed.
The study can be read here: [Royal Society Publishing]
The New Study
Loukola wanted to know whether bees could spontaneously solve a problem without any training on the solution itself.
The “Box‑and‑Banana”‑style Task
- An artificial flower was placed above a pit in the floor, leaving insufficient space for a bee to hover and reach the flower directly.
- A small ball sat in the pit. To access the flower, a bee would need to roll the ball into the pit and then climb on top of it.
“This is essentially an insect version of the classic ‘box‑and‑banana’ problem,” said Loukola. “The animal must realise that an object can be repositioned and then used as a tool to reach an otherwise inaccessible goal.” [EurekAlert press release]
Experimental Groups
| Group | Training | Goal |
|---|---|---|
| 1 | Trained to recognise the flower as a sugary reward and that the ball could be moved | Test spontaneous problem‑solving |
| 2 | Trained to recognise the flower as a reward but not that the ball was movable | Control for reward learning |
| 3 | No training | Baseline |
The authors emphasised that bees in Group 1 only learned the properties of the individual elements; any success therefore reflected spontaneous problem‑solving rather than gradual reinforcement learning.
Results
- Group 1 solved the task at a much higher rate than Groups 2 and 3.
- Bees in Group 1 made more attempts and interacted with the ball more efficiently and in a more structured manner.
- Performance of Groups 2 and 3 was similar and considerably poorer than Group 1.
These findings suggest that bumblebees can integrate separate pieces of information (the reward flower and the movable ball) to devise a novel solution without explicit training on the solution itself.
Take‑away
The study adds to a growing body of evidence that even insects with minuscule brains possess sophisticated cognitive abilities:
- Tool use and object manipulation can arise spontaneously.
- Cooperative behaviour may be intentional, not merely a by‑product of individual learning.
- Problem‑solving in insects can parallel classic animal‑cognition experiments traditionally reserved for mammals.
Future work should focus on detailed behavioural tracking to uncover the precise decision‑making processes that underlie these impressive feats.
To bee or not to bee
Credit: Olli Loukola / University of Oulu
The initial results were interesting, but Loukola et al. wanted to rule out the possibility that bees might have an inherent preference for rolling balls—i.e., that the act of rolling could be rewarding on its own. To test this, they ran 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, 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 succeeded in this task. Because the bees could still glimpse the flower once the ball was near the opening, the team repeated the experiment with three openings in the barrier to further limit visual feedback. In that version, there were no significant differences between trained and untrained (control) bees.
Final experiment – isolating goal‑directed performance
To separate genuine problem‑solving from accidental success and visual cues, the researchers built a rectangular arena with two invisible compartments.
- Pre‑training: 30 bees saw the flower positioned above one compartment.
- Test: The flower was hidden from the ball’s starting location; the bees had to move the ball into the correct compartment.
Results:
- 23 of the 30 bees succeeded.
- Of those 23, 16 did so without first moving the ball into the wrong compartment.
The authors noted that their setups could not track the bees’ gaze, posture, or other subtle cues that might reveal the exact “Eureka!” moment when the insects understood the problem. They suggest future work should probe 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:
(See “About DOIs”: )
About the author
Jennifer Ouellette is a senior writer at Ars Technica who focuses on the intersection of science and culture, covering topics from physics to her favorite films and TV series. She lives in Baltimore with her spouse, physicist Sean M. Carroll, and their two cats, Ariel and Caliban.
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