马在动物界属于睡得少的动物:每天只休息3个小时。但是对马来说,像图中这样躺着睡的情况是很罕见的:马睡觉的时候大部分都站着——有危险逼近,拔腿就跑。睡眠一直是科学界的一大谜题——动物界的睡眠也一样。生物学家发现,所有动物都要睡觉,不管是哺乳类、鸟还是鱼类。但它们怎么睡,则有很大的差异。 Horses in the animal world belong to less sleepy animals: only rest for 3 hours a day. But for a horse, it is rare to lie down and sleep like this: Most of the horses stand when they sleep - dangerously close and running. Sleep has always been a big mystery in science - the same goes for sleep in the animal world. Biologists have found that all animals have to sleep, whether mammals, birds or fish. But how do they sleep, then there is a big difference.