Alex Davidson/Queen Mary University
Bumblebees can process the duration of flashes of light and use the information to decide where to look for food, a new study has found.
This is the first evidence of such an ability in insects, according to doctoral student Alex Davidson and his supervisor Elisabetta Versace, a senior lecturer in psychology at Queen Mary University of London. The discovery could help settle a long-standing debate among scientists about whether insects are able to process complex patterns, Versace told CNN.
“In the past, it was thought that they were just very basic reflex machines that don’t have any flexibility,” she said.
To reach its finding, the team set up a maze through which individual bees would travel when they left their nest to forage for food.
Researchers presented the insects with two visual cues: one circle that would light up with a short flash and another with a long flash of light.
Approaching these respective circles, the bees would find a sweet food that they like at one, and a bitter food, which they don’t, at the other.
The circles were in different positions at each room in the maze, but the bees still learned over varying amounts of time to fly toward the short flash of light associated with the sweet food.
A 3D model of the apparatus used by the researchers
A 3D model of the apparatus used by the researchers
Alex Davidson/Queen Mary University
Davidson and Versace then tested the bees’ behavior when there was no food present, to rule out the possibility that the bees could see or smell the sugary food.
They found that the bees were able to tell the circles apart based on the duration of the flashes of light, rather than other cues.
“And so in this way, we show that the bee is actually processing the time difference between them to guide its foraging choice,” Davidson said.
“We were happy to see that, in fact, the bees can process stimuli that, during the course of evolution, they have never seen before,” Versace said, referring to the flashes of light.
“They’re able to use novel stimulus they have never seen before to solve tasks in a flexible way,” Versace added. “I think this is really remarkable.”
The researchers say bumblebees are one of only a small number of animals, including humans and other vertebrates such as macaques and pigeons, that have been found to be able to differentiate between short and long flashes, in this case between 0.5 and five seconds.
For example, this ability helps humans to understand Morse code, in which a short flash is used to communicate the letter “E” and long flash the letter “T.”
More than ‘just machines’
It is not clear how bees are able to judge time duration, but the team plans to investigate the neural mechanisms that allow the insects to do so.