Solution:The cocoons are placed in hot water to loosen the silk filaments.
To loosen the silk fibre, the cocoons are immersed in boiling water. After a month of eating mulberry leaves, the caterpillars stop eating the leaves and begin spinning their own cocoon. After a few weeks, they begin to shed their skin and develop into pupas within the cocoon. The pupa is killed by boiling, and the silk fibre becomes loose. Boiling aids in the incubation of the cocoon.