Kathy Mitchell, age 10, of Tulsa, Oklahoma, for her question:

What is a silkworm?

There are dozens of different silkworms and all of them are mothtype insects. All of them hatch from eggs into hungry little caterpillars. The silkworms of China and Japan devour nothing but mulberry leaves. But certain silkworms of Assam and other parts of India prefer to feed on the leaves of oak trees. When the silkworm caterpillars have satisfied their huge appetites, it is time for their pupa life stage. They spin long threads of silk and enfold themselves in soft cocoons.

In China, Japan and India silkworm moths are cultivated for their silken cocoons. Each cocoon is made from a single thread that is about a quarter of a mile long. It takes the silk from 25,000 cocoons to make about one pound of silk fabric. The silks from China and Japan can be dyed gorgeous colors. But some of the silkworms of India spin pale golden silk called tussah, which cannot be dyed.