A good night's sleep is a necessary part of life for all birds and mammals—including people. Scientists had thought, however, that insects don't need sleep. Now, researchers have found that fruit flies nap, too, and the discovery could help answer some pressing questions about sleep.
It's hard to tell if an animal as small as a fruit fly is sleeping or not, says Joan C. Hendricks, who led a group of researchers at the University of Pennsylvania that caught fruit flies, Drosophila melanogaster, stealing a few winks. Scientists usually measure an animal's brainwaves to determine if it's asleep, but fruit fly brains are too tiny for that.