Bees get buzz off caffeine, too.
BEES are just as addicted to the buzz of caffeine as coffee-mad humans, a study has found.
Scientists discovered the insects made a bee-line for sugar solution laced with the compound. They also performed "waggle dances" directing their hive mates to the caffeine source.
After a first taste of the coffee drug the bees kept returning to where they had found it before.
Researcher Dr Roger Schurch, from the University of Sussex, said: "We were surprised at how we saw an effect of caffeine just about everywhere we looked in foraging and recruitment, and all in the direction to make the colony more faithful to the source."
Many plants - not just coffee - have caffeine in their leaves, stems and seeds. About half of plant families also have some caffeine in their nectar.
To test the theory that plants have evolved a way to get bees hooked on caffeine, the scientists set up an experiment in which the insects could choose between two feeders placed the same distance from their hive.
Both contained a sugary solution attractive to bees, but only one contained caffeine. The caffeine not only drew the bees in, but also led them to pass the good news to other members of their colony.