Question

How do neptholine protect woollen clothes from attach of insect

Answer 1

 Very few insects have the ability to digest wool. Among the few which do are larvae of the webbing clothes moths (Tineola bisselliella) and the carpet beetles (Dermestidae). In Colorado, carpet beetles are far more common and damaging to woolens than are clothes moths....
Naphthalene balls possesses the characteristic of sublimation. When a substance becomes gas directly from solid state, it undergoes sublimation.  The gas generated from moth balls is toxic to moths and moths larvae.  The odor is unpleasant enough to keep moths and similar insects away from moth balls. Further, it is believed that when naphthalene gas is inhaled, other chemicals are produced in the body that damage cells and tissues. ..
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