Caffeine has been found to boost bees' memory and makes them better pollinators, according to a study published in the journal Science.
Honeybees fed a sugar solution containing caffeine, which exists naturally in the nectar of coffee and citrus flowers, were three times more likely to remember a flower's scent than those feeding on just sugar.
Bees that have fed on caffeine-laced nectar are laden with coffee pollen and these bees search for other coffee plants to find more nectar, leading to better pollination, researchers said.
The effect of caffeine on the bees' long-term memory was significant: three times as many bees remembered a floral scent 24 hours later and twice as many bees remembered the scent after three days.
The research team learned the nectar of certain citrus flowers, including grapefruit and lemons, and coffee flowers often contains low doses of caffeine.
Co-author Phil Stevenson of the University of Greenwich in Britain said the work helps scientists understand the basic mechanisms of how caffeine affects the brain.
"What we see in bees could explain why people prefer to drink coffee when studying," he said.
"Understanding a honeybee's habits and preferences could help find ways to reinvigorate the species to protect our farming industry and countryside."