Life cycle of a butterfly
Have you ever seen a baby butterfly? If you have seen a caterpillar（毛虫）, then you have!
This is called the larva stage（幼虫阶段）. Now let's learn about the life cycle of butterflies.
Some types of butterflies lay only one egg at a time. Other types lay up to a few hundred at a time! Caterpillars hatch（孵化）from the eggs. They are very tiny at first. The main job for caterpillars is to eat a lot and grow. They eat the leaves of the plant where they hatched.
They form a cocoon（蚕茧）around themselves. Some types of caterpillars stay in their cocoons for only a few days. Other types stay inside for many months. This change is called a metamorphosis（变形，尤指从蛹到昆虫）.
After the metamorphosis is done, they come out of their cocoons. But they are no longer worm-like babies! They are adult butterflies. They have beautiful wings. Most of them live only two to four weeks. None of them live more than one year. So they start laying eggs right away. The cycle starts again!
A. Adult butterflies do not live very long.
B. Butterflies lay eggs on plants.
C. But all of them go through an amazing change!
D. Caterpillars then begin the pupa stage（蛹阶段）.
E. Butterflies start their lives as worm-like caterpillars.
