HOW COME? Even bugs need their share of shut-eye
Do bugs sleep like other animals? asks a reader.So far, scientists have found that bees, fruit flies, cockroaches, moths, paper wasps, locusts and scorpions all enjoy (and require) a good snooze.
Of the known bug sleepers, it's honeybees and fruit flies that have been studied the most. Scientists say honeybees make good subjects because hive living makes them so social, and because their elaborate social life has been studied for so long.
Like us humans, bees tend to sleep mostly at night, antennae relaxed and slumping. Bees also squeeze in naps during the morning or afternoon. During a bee's long sleeps, researchers have observed short bursts of movement in the antennae, rather like a person's "rapid eye movements." This may indicate that bee sleep involves distinct phases, including dreaming. And just like sleep-deprived people, bees kept up one night tend to sleep more the next.
Scientists say that while we sleep, the brain does its daily cleaning and organizing, erasing nonessential memories and consolidating and storing others. Something similar seems to happen in the nervous systems of sleeping bugs. In 2012, a study in Germany used radio frequency identification devices to track honeybees as they flew. To see how sleep deprivation affects honeybee memory, researchers set up a hive and a movable feeding station. Then they trained groups of bees to fly to the feeder and return to the hive.
After the route had been committed to bee memory, the scientists collected bees busy at the feeder -- and released them at a brand-new location. Which left the bees wondering: Which way was home? By their second try, the bees had memorized the new route. And if the bees had been sleep-deprived before their first trip to the undisclosed location, they still managed to find their way back to the hive.
Then researchers conducted a new experiment. A group of bees was similarly released in the unfamiliar location, and, like the first group, tried to find their way home. But there was a twist: Later that night, scientists kept the bees from sleeping, shaking them awake every few minutes.
The next day, when the bees were once again removed from the feeder and released in the unfamiliar area, their new-route memories proved fragile. Unlike the well-rested first group, which easily found their way home on the second day, only half of the sleep-deprived bees made it back to the hive. And those that did also took twice as long to get there as bees had in the well-rested group.
Unlike the bees that had slept deeply between their first and second tries at the new route, the sleep-deprived group had not consolidated the fledgling memory of the flight path. Likewise, a recent study found that students who slept just after studying were better at remembering the new material the next day.