Household Casebearer (often confused with Plaster Bagworm)

Natural Habitat

Primarily indoors in humid environments; frequently found on walls, in corners near floors, in closets, and underneath spider webs in basements or garages.

Diet & Feeding

Detritivore; feeds on old spider webs, wool, hair, lint, dead insects, and general household dust/debris.

Behavior Patterns

The larva constructs a protective flat, pumpkin-seed-shaped case out of silk and debris (sand, dust, lint) which it drags around as it moves. It has openings at both ends allowing the larva to turn around inside without leaving the case. They eventually pupate inside this case.

Risks & Benefits

Generally harmless to humans (does not bite or sting). Can be a minor pest if they damage wool clothing or rugs, though they primarily eat cobwebs and dust. Their presence often indicates high humidity or dusty conditions.

Identified on: 3/2/2026