每當看到蟲子們那一對對大眼睛,我們都會產生疑惑,它們沒有眼皮,怎么睡覺呢?原來,這與快速動眼期有關。這是一個睡眠的階段,是全部睡眠階段中最淺的,眼球在此階段快速移動,大腦神經元的活動也與大腦清醒的時候相同,而這種現象發生在所有哺乳類動物和鳥類動物身上。

Ever wonder why bugs are so bug-eyed?
Night crawlers
While a still bug might look like dozing, the creepy crawler is merely relaxing. Neuroscientists distinguish sleep from rest by pointing to specific kinds of brain activity, like dreaming, that take place when the body is in an immobile state.
According to neurological criteria, insects do not actually sleep.
Neither do fish, amphibians or mollusks. Lizards and mammals, on the other hand, need to catch their z’s.
REM Sleep
REM, or Rapid Eye Movement, sleep is thought to be associated with dreaming, and is required by a particularly complex kind of brain. REM sleep is common to humans and nearly all mammals. Birds also get REM sleep, but only in the early part of their lives.
Koalas and Congressmen are alike that they both need their shut-eye to recharge, while your average mollusk and insect stay OPEN 24 hours a day.
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