MIAMI • An unexpected sugary snack can give bees a little buzz and appears to lift their mood, even making them optimistic, according to new research that suggests pollinators have feelings, too.

Since emotions are subjective and difficult to measure - particularly in animals - researchers looked at how bees' behaviour changed after a sip of sucrose solution. They found that bees learnt to fly faster to a container with a sugary drink inside than to one with just water.

"Bees given a 60 per cent sucrose reward to induce a positive affective state flew faster to the cylinder than non-rewarded bees," said the study, published on Thursday in the journal Science.

"Much like happy people are more likely to make optimistic judgments about ambiguous situations," said the lead author, Dr Clint Perry, at the University of London.

The sugar-buzzed bees also appeared to recover faster from a scare - when they were briefly caught and released, as if attacked by a predator spider - than bees that had not had the sweet treat.

"Sweet food can increase positive emotions and improve negative mood in human adults, and reduce crying and grimacing of newborns in response to aversive stimuli," said the study.

"If drinking an unexpected sucrose solution caused a positive emotion-like state in bees, we predicted that, after consumption, bees' aversive reaction to the 'predator' would be attenuated.

"Indeed, bees that consumed sucrose solution before the 'attack' took less time to reinitiate foraging."

Much remains to be understood, however, about what bees may be feeling, and how it matters to their survival.

AGENCE FRANCE-PRESSE