James Gorman in The New York Times:
Caffeine improves learning and memory in bees, as it does in people. Scientists know that. But, one might wonder, what do these laboratory findings mean in terms of the actual lives of bees? It’s not as if a flower meadow is sprinkled with coffee shops. Except that it is, in a way. Up to 55 percent of flowering plants are estimated to have caffeinated nectar. So any meadow or forest is going to have lots of places to stop by for a jolt. Margaret J. Couvillon of the University of Sussex, who studies the behavior of honeybees, wanted to see how caffeine affected bees’ behavior.What she found was that bees were drawn to caffeine like office workers to a coffee cart and that the favorite drug of so many human beings changed how bees evaluated nectar quality.
As they reported in the journal Current Biology Dr. Couvillon and her colleagues at the university, including Roger Schurch (her husband) and Francis L. W. Ratnieks, trained two groups of bees to go to two different feeders. They were filled with the same nectar, but one had caffeine in about the same concentrations common in flowers. The caffeinated bees visited their feeder more often than the other bees. They were more loyal to their feeder. And they persisted in coming to the feeder for days after it was emptied, which the other bees did not.
And they danced up a storm.