Bumblebees have positive emotions after drinking small droplets of sweet sugar water, biologists in east London have discovered.

East London Advertiser: Bees tagged in Queen Mary University study [photo: Joseph Woodgate]Bees tagged in Queen Mary University study [photo: Joseph Woodgate] (Image: Joseph Woodgate/QMUL)

Insects that have emotional states in relatively simple nervous systems opens up new avenues for research, a study at Queen Mary University suggests.

The findings follow experiments when tagged bees were released from the rooftop of the university campus in Mile End earlier this year.

The researchers trained bees to find food at a blue flower and no food at a green flower, then tested them on a new blue-green flower.

Bees that had drunk a droplet of sugar water took less time to land on the ambiguous-coloured flower.

It showed that sweet sugar water may be causing a positive emotion-like state in bees, similar to humans and other animals.

Understanding basic features of emotional states helps to determine the brain mechanisms underlying emotion in all animals, say researchers.

Prof Lars Chittka urged: “The finding that bees exhibit emotion-like states as well as surprising levels of intelligence indicates that we should respect their needs and do more for their conservation.”

Sweet food can improve negative moods in adult humans and reduce babies crying in response to negative events, the researchers point out. The experiments showed similar cognitive responses in the bees.

The bees were subjected to a simulated ‘spider attack’, copying something common in nature. Those that drank the sugar water took less time to restart their foraging after the attack.

The researchers are hoping for further investigation into how small rewards affect bees’ perception of the world, how emotions may have evolved and determine the underlying mechanisms of emotional states in the brain. The results have been published in the journal Science.