小区里、校园里高高的树上常常可以看到鸟巢，我们理所当然的认为这就是鸟儿的家，是鸟儿"睡觉"的地方。然而事实果真如此吗？如果鸟儿不是在巢里睡觉的话，又是在哪儿睡的呢？鸟巢如果不用来睡觉，又是用来做什么的呢？

Many people believe that a bird's home and place to sleep is it's nest, but there is no scientific evidence to support this idea.

Zoologist observing birds found that they don't roost overnight in their nests, even if a storm is coming. Mallard ducks and swans often tuck their heads between their wings and bodies and float on the water at night. Cranes, with their long legs, are fond of sleeping on the ground.

Since they don't sleep in the nest, why do birds still build nests? Birds usually lay and hatch eggs in their nests. After the eggs hatch, the nest becomes a place for the mother bird to care for her chicks. The nest soon becomes crowded as the chicks grow. After a while, there is no longer room for the mother in the nest. After the chicks grow into adult birds, the nests are abandoned. In short, there are nine thousand species of birds on the earth and most of them only use nests for breeding. They don't sleep in them at night.

（北京林业大学通讯员黄典钰供稿 英语点津 Annabel 编辑）