Buff-tailed bumblebees (Bombus terrestris) can decide where to forage for food based on different durations of visual cues, according to new research.
The ability to process temporal information is crucial for animal activities like foraging, mating and predator avoidance. While circadian rhythms have been extensively studied, there is limited knowledge regarding how insects process durations in the range of seconds and sub-seconds. Davidson et al. aimed to assess buff-tailed bumblebees’ (Bombus terrestris) ability to differentiate the durations of flashing lights in a free-foraging task. Image credit: Myriam.
In Morse code, a short duration flash or ‘dot’ denotes a letter ‘E’ and a long duration flash, or ‘dash’, means letter ‘T’.
Until now, the ability to discriminate between ‘dot’ and ‘dash’ has been seen only in humans and other vertebrates such as macaques or pigeons.
Queen Mary University of London Ph.D. student Alex Davidson and colleagues studied this ability in Bombus terrestris bumblebees.
They built a special maze to train individual bumblebees to find a sugar reward at one of two flashing circles, shown with either a long or short flash duration.
For instance, when the short flash, or ‘dot,’ was associated with sugar, then the long flash, or ‘dash,’ was instead associated with a bitter substance that bumblebees dislike.
At each room in the maze, the position of the ‘dot’ and ‘dash’ stimulus was changed, so that bumblebees could not rely on spatial cues to orient their choices.
After bumblebees learned to go straight to the flashing circle paired with the sugar, they were tested with flashing lights but no sugar present, to check whether bumblebees’ choices were driven by the flashing light, rather than by olfactory or visual cues present in the sugar.
It was clear the bumblebees had learnt to tell the light apart based on their duration, as most of them went straight to the ‘correct’ flashing light duration previously associated with sugar, irrespective of spatial location of the stimulus.
“We wanted to find out if bumblebees could learn to the difference between these different durations, and it was so exciting to see them do it,” Davidson said.
“Since bumblebees don’t encounter flashing stimuli in their natural environment, it’s remarkable that they could succeed at this task.”
“The fact that they could track the duration of visual stimuli might suggest an extension of a time processing capacity that has evolved for different purposes, such as keeping track of movement in space or communication.”
“Alternatively, this surprising ability to encode and process time duration might be a fundamental component of the nervous system that is intrinsic in the properties of neurons. Only further research will be able to address this issue.”
The neural mechanisms involved in the ability to keep track of time for these durations remain mostly unknown, as the mechanisms discovered for entraining with the daylight cycle (circadian rhythms) and seasonal changes are too slow to explain the ability to differentiate between a ‘dash’ and a ‘dot’ with different duration.
Various theories have been put forward, suggesting the presence of a single or multiple internal clocks.
Now that the ability to differentiate between durations of flashing lights has been discovered in insects, researchers will be able to test different models in these ‘miniature brains’ smaller than one 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 across different species, including insects, to shed light on the evolution of those abilities.”
“Processing durations in insects is evidence of a 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 November 12, 2025 in the journal Biology Letters.
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Alexander Davidson et al. 2025. Duration discrimination in the bumblebee Bombus terrestris. Biol. Lett 21 (11): 20250440; doi: 10.1098/rsbl.2025.0440
