Bees learn to read ‘light code’ in study of insect intelligence

In a study on insect intelligence, researchers have successfully trained bumblebees to distinguish between short and long flashes of light, a simplified form of Morse code, to locate sugary rewards, Biology Letters published on Wednesday.

The experiment, led by behavioral scientist Alex Davidson at Queen Mary University of London, marks the first time Bombus terrestris have been shown to make foraging decisions based purely on the duration of a visual signal.

"We wanted to find out if bumblebees could learn the difference between these different durations, and it was so exciting to see them do it," Davidson said.

The bees were presented with two flashing lights inside a small foraging arena, one flashing for a longer duration and another for a shorter one. One flash pattern was linked to a sugary treat, while the other was tied to a bitter quinine solution.

In some tests, the long flash lasted five seconds and the short one just a second. Other experiments used durations of 2.5 and 0.5 seconds. Once bees consistently chose the correct pattern, the researchers removed the rewards to confirm that they had learned the timing pattern rather than following scent cues.

Even without sugar present, the bees continued to pick the light pattern previously linked to the reward more often than chance would predict, showing they could distinguish between the two durations.

"Since bees don't encounter flashing stimuli in their natural environment, it's remarkable that they could succeed at this task," Davidson said.

"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."

He added that this ability to measure time might be a fundamental feature of the nervous system itself.