Unbeknown to many people, the silk worm in its pupa stage dies when its silk thread is removed.
The silk worm spins its silk thread encasing itself in this protective cocoon, the thread is almost 1 kilometer long (900meters). The silk is a protein that is a food source it relies on as it develops into a silk moth. But it is the process used to remove the silk that kills the pupa.
In Southern India, they are against the killing of the pupa and use a different process - their silk is known as peace silk or Ahisma Silk.