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FancyEnglish            A Bug's Sleep          百科知识

VOA -- English Central A Bug's Sleep A Bug's Sleep. Every mammal needs sleep, as do birds and reptiles, such as snakes. But what about insects? Do they need sleep? Scientists have been trying to discover the truth about insect sleep behavior for years. Scientists first thought insects did not need sleep. According to them, the insect brain was not complex enough to need it. Scientists said that some kinds of brain activity, like dreaming, were sleep behaviors. Insects do not dream, so scientists said that they did not sleep. They believed that insects rested, instead. However, new studies have shown that some insects may actually sleep. There are four types of behavior during sleep. First, sleeping people and animals don't move much. Also, they have a position for sleeping. For example, they lie down. Additionally, they don't wake up easily when hearing noises or seeing light. Lastly, they are able to come out of sleep quickly in response to some intense stimulant. Scientists have now seen similar behaviors in fruit flies. For example, fruit flies become still every night for about seven hours. At these times, they sit in a different way, let their antennae drop and do not respond to quiet noises. The flies do begin to move around when louder noises are made. Scientists think that some insects may have their own unique kind of sleep.