Bumblebees can learn to understand a simple kind of Morse code and differentiate between long and short light flashes, according to a new study.
Researchers have shown for the first time that the fuzzy insects can make decisions on where to go based on whether they see a short-duration “dot” or a long-duration “dash”.
This ability has previously only been reported in humans and other vertebrates such as macaques or pigeons, but scientists at Queen Mary University of London (QMUL) said it was “exciting” to learn bees could do the same.
The team built a special maze to train individual bees to find a sugar reward, which they placed at one of two flashing circles. In the other flashing circle, they placed a bitter substance that bees dislike.
They then used the light circles to flash either a long or short duration, building an association of the “dot” flash with sugar and the “dash” with the unpleasant substance.
At each room in the maze, the position of the flashing circles was changed, so that bees could not rely on cues around them to orient their choices.
After the insects learned to go straight to the flashing circle paired with the sugar, researchers tested them with flashing lights but no sugar present to check whether bees’ choices were driven solely by the flashing light.
They said it was “clear” the bees 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.
PhD student Alex Davidson said it was “remarkable” to see the bees learn to differentiate between the dot and dash signals.
“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,” he explained.
“Since bees don’t encounter flashing stimuli in their natural environment, it’s remarkable that they could succeed at this task.”
He said the fact that the insects could track the duration of the flashing lights could potentially be attributed to 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,” he continued.
“Only further research will be able to address this issue.”
The team said now bees’ ability to recognise light durations had been proven, they will be able to test different models in the insect’s tiny brains - smaller than one cubic millimetre - to understand why.
