Study: Bumblebees Can Be Trained to Read Simple ‘Morse Code’

Buff-tailed Bumblebees (Terrestrial Bombus) can decide where to look for food based on different durations of visual cues, new research shows.

The ability to process temporal information is crucial for animal activities such as foraging, mating, and predator avoidance. Although circadian rhythms have been studied extensively, knowledge of how insects process durations between seconds and subseconds is limited. Davidson and others. aimed to assess buff-tailed bumblebees (Terrestrial Bombus) ability to differentiate durations of flashing lights in a free foraging task. Image credit: Myriam.

In Morse code, a short duration flash or “dot” means a letter “E” and a long duration flash, or “dash”, means the letter “T”.

Until now, the ability to distinguish between “dot” and “dash” has only been observed in humans and other vertebrates such as macaques or pigeons.

Ph.D. from Queen Mary University of London. student Alex Davidson and his colleagues studied this ability in Terrestrial Bombus bumblebees.

They built a special maze to train individual bumblebees to find a sugar reward in one of two flashing circles, depicted with a long or short flash duration.

For example, when the short flash, or “dot,” was associated with sugar, the long flash, or “dash,” was instead associated with a bitter substance that bumblebees don’t like.

In each room of the maze, the position of the “dot” and “dash” stimuli was changed, so that the bumblebees could not rely on spatial cues to guide their choices.

After the bumblebees learned to head directly toward the flashing circle associated with the sugar, they were tested with flashing lights but no sugar present, to test whether the bumblebees’ choices were driven by the flashing light, rather than by olfactory or visual cues present in the sugar.

It was clear that the bumblebees had learned to discriminate light based on its duration, as most of them headed directly toward the “correct” flashing light duration previously associated with sugar, regardless of the spatial location of the stimulus.

“We wanted to know if bumblebees could learn to tell the difference between these different durations, and it was so exciting to see them do it,” Davidson said.

“As bumblebees do not encounter flashing stimuli in their natural environment, it is remarkable that they can succeed in this task.”

“The fact that they can track the duration of visual stimuli might suggest an extension of a time-processing capacity that evolved for different purposes, such as tracking movement in space or communication.”

“Alternatively, this surprising ability to encode and process duration could be a fundamental component of the nervous system intrinsic to the properties of neurons. Only further research can resolve this issue.”

The neural mechanisms involved in the ability to track time during these durations remain mostly unknown, because the mechanisms discovered for training with the daylight cycle (circadian rhythms) and seasonal changes are too slow to explain the ability to differentiate between a “dash” and a “dot” of different duration.

Various theories have been put forward, suggesting the presence of one or more internal clocks.

Now that the ability to differentiate the durations of flashing lights has been discovered in insects, researchers will be able to test different models in these “miniature brains” smaller than a cubic millimeter.

“Many complex animal behaviors, such as navigation and communication, depend on time processing abilities,” said Dr. Elisabetta Versace, a researcher at Queen Mary University of London.

“It will be important to use a broad comparative approach between different species, including insects, to shed light on the evolution of these abilities.”

“Processing times in insects are evidence of complex task solution using minimal neural substrate.”

“This has implications for complex cognitive-like traits in artificial neural networks, which should seek to be as efficient as possible to be scalable, taking inspiration from biological intelligence.”

The results were published on November 12, 2025 in the journal Biology letters.

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Alexander Davidson and others. 2025. Duration discrimination in the bumblebee Terrestrial Bombus. Biol. Lett 21(11):20250440; doi: 10.1098/rsbl.2025.0440