Carpet beetles and clothes moths attack fibre of animal origin, avoiding the synthetic fabrics.

Even synthetics may be attacked if they are soiled by food or animal excrement. The blending of animal fibres and synthetic fibres is now commonplace and make such textiles susceptible to carpet beetle and moth damage.
Both carpet beetles and moths prefer secluded areas such as behind curtains and furniture where they are seldom disturbed {Piano,couch,tables,entertainment units}. In each instance, it is the larva that will cause damage to carpet and other fabrics.