Giraffes don't get very much sleep, either-only about two hours a night. For giraffes, sleeping is awkward and can even be dangerous. A giraffe remains standing for most of its short sleep, although it may lean its head on a branch so as not to strain its neck. Like elephants, giraffes need to lie down during the dreaming stage of sleep, which lasts about 20 minutes. It can take a whole minute for a giraffe to get back up on its long legs again. During these times, the giraffe has few defenses if it is attacked by a predator.
Why do large animals sleep so little? Scientists aren't sure. It may be that large animals stay awake because they need to spend so much time eating and looking for food.
All animals, except the predators at the top of the food chain, are vulnerable while they sleep. Some seek a sheltered place-a den or a nest or a burrow-to sleep.
When a mouse is tucked away in its hidden nest, it's less likely to become dinner for another animal. That may be one reason why small animals sleep so much.
Some animals that can't hide so easily keep safe by staying alert and sleeping very little. Sheep sleep for only about four hours a day, but they spend another four hours in a state of drowsiness or dozing. This rests their bodies while keeping them awake enough to sense danger.
Horses need about three hours of sleep a day. But horses can sleep on their feet, so they're always ready to run away. They don't topple over while sleeping because their legs lock in place.
From the time of its birth, an antelope is always alert for danger. Its only defense from all the animals that want to eat it is to flee. Newborn antelopes are running around within seconds of being born. Like sheep and other grazing animals, antelopes can't afford to spend long hours sleeping.
Predators, such as lions, tend to sleep more than their prey do. And they spend more time in dreaming sleep than their prey do, too, although scientists don't know why. Except for brief periods when the lion is hunting, it takes life slowly, lazing about, playing, and sleeping about 14 hours a day.
Even asleep, a lion can feel safe. After all, who is going to attack a sleeping lion?
Poor things, they must be knackered!!!
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