Another way of getting caterpillars is to look for them on the under sides of the leaves of such plants as the nettle, the rose, and the hawthorn. You must feed these caterpillars on the leaves of the plant on which you found them; and as they are very greedy, they will want some fresh leaves every day.
还有一种办法能捉到鳞翅目幼虫，就是到荨麻、玫瑰、山楂这些植物的叶子下面去找。在什么植株上找到的幼虫， 就要用什么叶子来喂；这些幼虫很贪吃，每天都要吃掉一些新鲜叶子。
The body of the caterpillar grows, but its skin does not grow. When the old skin becomes too tight, it splits down the back, and the caterpillar crawls out. A new and larger skin soon grows on its body. The caterpillar then eats up its old skin.
幼虫的身体会长大，但皮肤却不长大。旧的皮肤变得太紧了，就从背部裂开，幼虫会从旧皮里面爬出来，很快长出更大的新皮肤。然后幼虫就把旧皮吃掉了。
This happens about five times before the creature grows to its full size. Then it stops feeding, and its body changes into what is called a chrysalis. The silk-worm caterpillars wrap themselves round with a ball of silk called a cocoon while they are going through this change. Others cover themselves with a hard brown case of skin.
这个过程要重复大概五次，幼虫才能长到最大。然后幼虫就不吃东西了，身体变成了“茧”，英语是chrysalis。蚕的幼虫这样变化的时候，会把身体包在一个蚕丝做的球形壳子里面，这壳子叫“蚕茧”（cocoon）。其他种类的幼虫，则会用一层坚硬的棕色壳子，盖住自己的身体。
Then after a time the case or the cocoon breaks open, and a perfect insect (a butterfly or a moth) creeps out, ready to fly about and to lay some tiny white eggs.
过了一段时间，壳子或者茧就会破开，一只成虫（蝴蝶或者蛾子）爬出来，准备翩翩飞舞，产下小小的白色虫卵了。
Do you see the caterpillar's small black head? It has a strong pair of jaws, and with them it eats every day a great many leaves. Look also at the hairs on its back. These hairs have two uses. They prevent birds from eating the caterpillar, for the bird does not like these hairs to stick in its throat; and, besides, if the caterpillar falls from a leaf to the ground, the hairs break the fall, and keep it from being hurt.
你看见幼虫的小黑脑袋了吗？ 幼虫有一对强壮的上下颚，用这对上下颚，每天都要吃掉很多叶子。再看看背上的毛。这些毛有两个用途：可以保护幼虫不被鸟吃掉，因为鸟不喜欢这些毛扎在喉咙里；而且，如果幼虫从叶子上掉了下去，这些毛可以起到缓冲的作用，不让幼虫摔伤。