Many people do not know how silk is being made and where it comes from, here some information:
How is Silk Made?
Mass-produced silk is made from domesticated silkworms, Bombyx mori, raised on farms. The silkworms, who are in the caterpillar stage of the silk moth, are fed mulberry leaves until they are ready to spin cocoons and enter their pupal stage. The silk is secreted as a liquid from two glands in the caterpillar's head. While they are still in their pupal stage, the cocoons are placed in boiling water, which kills the silkworms and begins the process of unraveling the cocoons to produce silk thread.
If allowed to develop and live, the silkworms would turn into moths and chew their way out of the cocoons to escape. The chewed silk strands would be much shorter and less valuable than the whole cocoons.
Approximately 15 silk worms are killed to make a gram of silk thread, and 10,000 are required to make a silk sari.
Other Methods of Silk Production
Silk thread can also be produced by killing silkworms while they are in their caterpillar stage, just before they spin their cocoons, and extracting the two silk glands. The glands can then be stretched into silk threads known as silkworm gut, which is used mainly to make fly fishing lures.
Silk can also be made without killing the caterpillars. Eri silk or "peace silk" is made from the cocoons of Samia ricini, a type of silkworm who spins a cocoon with a tiny opening in the end. After metamorphosizing into moths, they crawl out of the opening. This type of silk cannot be reeled in the same way that Bombyx mori silk is reeled, and instead is carded and spun like wool. Eri silk represents a very small portion of the silk market.
Another type of silk is Ahimsa Silk, which is made from the cocoons of Bombyx mori moths after the moths chew their way out of their cocoons. Because of the chewed-through strands, less of the silk is usable for textile production and Ahimsa silk costs more than conventional silk. "Ahimsa" is the Hindu word for "non-violence." Ahimsa silk, though popular with Jains, also represents a very small portion of the silk market.
If you would like to know more about how the silk worm creates their cocoon check out this link: