

For decorative display or degum them and gently pull the silk threads from the end of the cocoon to get a long length of silk thread for spinning, paper making or embellishment.
For a wonderful article on silkworms and degumming them:
http://www.knitty.com/ISSUEspring06/FEATbombyx.html
Information on the Silkworm:
The silkworm (Bombyx mori, Latin: "silkworm of the mulberry tree") is the larva or caterpillar of a moth in the family Bombycidae, that is very important economically as the producer of silk. It is entirely dependent on humans for its reproduction and no longer occurs in the wild; silk culture has been practised for at least 5,000 years in China (Goldsmith et al., 2004). A silkworm's diet consists solely of mulberry leaves. It is native to northern China.
The cocoon is made of a single continuous thread of raw silk from 300 to 900 meters (1000 to 3000 feet) long. The fibers are very fine and lustrous, about 10 micrometers (1/2500th of an inch) in diameter. About 2,000 to 3,000 cocoons are required to make a pound of silk.
If the larvae is allowed to survive after spinning its cocoon, it will make a hole in the cocoon when it exits as a moth. This would cut short the threads and ruin the silk. Instead, silkworm cocoons are boiled. The heat kills the silkworms and the water makes the cocoons easier to unravel.
These cocoons still have the silkworm larvae inside.
These beautiful solar dyed bombyx silk cocoons are available in my Etsy store. Available in each of the seven colors with six cocoons per bag or a variety pack with one of each of all seven colors and as a bag of six cocoons - three Navy blue and three Emerald Green and as a bag of seven cocoons - four Purple and three Pumpkin Gold.