小區里、校園里高高的樹上常常可以看到鳥巢，我們理所當然的認為這就是鳥兒的家，是鳥兒"睡覺"的地方。然而事實果真如此嗎？如果鳥兒不是在巢里睡覺的話，又是在哪兒睡的呢？鳥巢如果不用來睡覺，又是用來做什么的呢？

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.

（北京林業大學通訊員黃典鈺供稿 英語點津 Annabel 編輯）