Every year some birds fly south when days turn cold and leaves from trees start to fall. They travel a very long way to find a warmer winter. This travel is called migration (迁徙).
Birds do that because in winter most of the plants die and some insects (昆虫)hide. They fly away to find enough food. The next year when there is plenty of food for them to eat, they will come back.
Birds fly in some ways. For example, they fly in groups like the letter V or in a row. The trip is often hard and it may be dangerous. But they never get lost because they look at the sun, the moon and stars.
The Migration of | |
When they fly south | Days turn cold and from trees start to fall. |
What the purpose is | They fly away in to find enough food. |
the trip is | It is often hard and dangerous. |
they never get lost | Because they look at the sun, the moon and stars. |