Silk moth that contain silk is called Cocoon.

Cocoon - The Protective Covering of Silk Moth

The silk moth is a type of insect that belongs to the family of moths. The silk moth produces silk, which is a natural protein fiber. The silk is produced by the silk gland of the silk moth, and it is used to create the protective covering of the silk moth, which is called a cocoon.

Formation of Cocoon

When a silk moth is ready to pupate, it spins a cocoon around itself using the silk that it produces. The cocoon serves as a protective covering for the silk moth during the pupal stage of its life cycle. The cocoon is made of a single thread of silk that is spun in a spiral pattern. The silk is sticky when it is first produced, but it hardens when it comes into contact with the air.

Harvesting of Silk

The silk inside the cocoon is harvested by cutting the cocoon open and removing the silk. However, this process kills the silk moth inside the cocoon. To prevent this, silk farmers often boil the cocoon before removing the silk. This kills the silk moth inside the cocoon, but it also makes the silk easier to remove.

Conclusion

The silk moth that contains silk is called a cocoon. The cocoon is a protective covering that is spun by the silk moth during the pupal stage of its life cycle. The silk inside the cocoon is harvested to create silk fabric, but this process often kills the silk moth inside the cocoon.