Changes in the insect during metamorphosis are miraculous. The tissues and organs of the larva are broken down and reassembled. The result is to produce a winged, adult insect, completely different from the wingless eating machine of its youth. The insect stage that harbors these changes is the pupa, from the Latin word for doll. Apparently, ancient people saw in the insect form a likeness to the inanimate toy for a child.
Insects protect their pupae in a variety of ways.
Some, like the common housefly, are thrifty, using their last larval skin to form a protective cover for the pupae. Still others follow the Boy Scouts' lead and make a tent-like structure by tying the edges of leaves together. Some insects spare no expense or trouble to make their cocoons. Probably the most famous of this group is the silkworm, which spins a cocoon of silk for pupation. Centuries ago, it was discovered that the silken thread used by silkworm larvae to construct pupation chambers could be unwound and used for human purposes.