Household casebearer (plaster bagworm)

Humid indoor areas, especially walls, ceilings, floors, closets, garages, and porches; also sheltered outdoor surfaces.

Larvae feed on lint, hair, dead insects, cobwebs, and other organic debris, occasionally consuming old insect remains or natural fibers. Adults generally do not feed.

The larva lives inside a portable, spindle-shaped silken case that collects dust and fibers, crawling slowly while attached to surfaces. It pupates within the case; adults are rarely noticed and reproduction is favored by humidity.

Harmless to people and pets and does not bite or sting. Usually causes little damage, though heavy infestations indicate excess moisture and larvae may scavenge or occasionally damage stored natural-fiber materials.