Household Casebearer or Plaster Bagworm

Natural Habitat

Typically found indoors in humid climates; common on walls, baseboards, and in corners of garages or basements. They thrive in warm, high-humidity environments.

Diet & Feeding

The larva feeds on spider webs, old silk/cocoons, wool, pet hair, dropped human hair, and dead insect parts. They are detritivores.

Behavior Patterns

The larva constructs a protective, flattened, pumpkin-seed-shaped case made of silk and debris (sand, soil, fibers). It drags this case around while feeding. Inside the case, the larva can turn around to feed from either end. Before pupation, it attaches the case to a vertical surface (like a wall).

Risks & Benefits

Generally considered a harmless nuisance. They do not bite or sting humans. While they can feed on wool and natural fibers, they are rarely abundant enough to cause significant structural or textile damage compared to clothes moths. They are beneficial in a minor sense as they clean up cobwebs and dead insects.

Identified on: 2/19/2026