Earnest Hemingway once said: “I love sleep. My life has the tendency to fall apart when I’m awake, you know?” We know what sleep deprivation does to the human mind and body, but is it the same for insects? Do insects need to sleep in order to function? Are bugs even capable of sleep?
“Yes—with an asterisk,” says Barrett Klein, a biologist at the University of Wisconsin, who studies the sleeping lives of honeybees. Some insects like praying mantises, paper wasps, fruit flies and cockroaches doze. Other insects enjoy a sleep-like state called torpor.
Insects have central nervous systems and internal circadian rhythms which both seem necessary to induce sleep-like states.
It’s difficult to measure sleep in insects, but we can ascertain what happens to them when they don’t rest. Butterflies find a place to rest in the late afternoon. When they are deprived of sleep, they don’t forage as well and female butterflies will lay their eggs on the wrong kinds of plants.
One study found that fruit flies slept at night and that sleep could be disrupted by the effects of caffeine, which is a good way to get rid of bugs. When deprived of sleep, fruit flies’ memory performance was affected and they needed to nap longer when they did get a chance to rest. When deprived of sleep for extended periods, about a third of the fruit flies died.