Silkworms have to retreat five times in their lives, respectively, from ants to spit silk cocoon to retreat four times, in the cocoon to molt once.

The first molt, no obvious symptoms, is not eating.

The second molt, there will be a small yellow spot on the head, or do not eat, with the skin molt, the head of the small yellow spot will become white little by little, the skin in the slow backward, after the molt, the mouth will become white, will not eat, to be a couple of days, the mouth changed color, the silkworms will be crazy to eat up.

The third, fourth and fifth molts are the same as the second.

Nothing changes after the molt, just a new skin.