“Carpet worms” are usually carpet beetle larvae, which feed on natural fibers, lint, and pet hair.
What they are
“Carpet worms” are the larvae of carpet beetles (Anthrenus and Attagenus species), 1/8 to 1/4 inch long, bristly and brown. They are not true worms.
What they eat
Natural fibers like wool, silk, fur, feathers and leather, plus lint, hair, pet fur and dead insects. Synthetic carpet is less affected.
How they arrive
Adults fly in from outdoors, laying eggs on flowers or in dark spots. Larvae live for 2 months to 1 year.
Signs
Shed skins, holes in fabric and small bristly larvae.
Control
- Vacuum carpets and furniture often.
- Wash clothes in hot water.
- Seal food and clean up pet hair.
- Insecticides if heavy infestation.
Harmless
They don’t bite, but hairs may cause itchy skin in some people.
What carpet worms are
“Carpet worms” are usually the larvae of carpet beetles (Anthrenus and Attagenus species) or, less often, clothes moth larvae. Carpet beetle larvae are small, 3 to 5 millimeters long, hairy or bristly and brown or striped. They are not true worms. Adults are 2 to 4 millimeters long, rounded and speckled, and they live outdoors on flowers.
What they eat
Larvae feed on natural fibers that contain keratin: wool, silk, fur, feathers, leather and hair. They also eat dead insects, pet hair, lint and dried foods like grains. They typically damage wool carpets, upholstered furniture, clothing and stored items. Synthetic fibers are rarely eaten unless soiled with food or sweat.
How they arrive
- Adult beetles fly in through open windows and doors, then lay eggs indoors.
- They are brought in on cut flowers, plants and infested items such as second-hand furniture.
- Bird nests, wasp nests and rodent carcasses in attics and walls can be a source.
- Each female lays 30 to 100 eggs, which hatch in 1 to 3 weeks.
Signs
- Small irregular holes in wool or fabric.
- Shed larval skins, which are small and bristly, and tiny fecal pellets.
- Live larvae or adults near windows.
- Itchy, red bumps on skin from contact with larval hairs, which are sometimes mistaken for bed bugs.
Control
- Vacuum carpets, upholstery, baseboards, closets and under furniture thoroughly, then empty the vacuum outdoors.
- Wash infested clothing in hot water above 120 F or dry clean it. Freezing items for several days kills larvae.
- Store wool and fur items in sealed containers.
- Remove bird, wasp nests and dead insects from attics.
- Use insecticides labeled for carpet beetles in cracks and crevices, or hire a pest control professional for larger infestations.
- Keep window screens in good repair.
Harmless
Carpet beetles do not bite or transmit disease, and are a nuisance mainly because of damage to belongings. Larval hairs can cause skin irritation or allergic reactions in some people.
Life cycle and damage
Carpet worms are usually the larvae of carpet beetles (Anthrenus and Attagenus species). Adult beetles are about 1/8 inch long, feed on pollen outdoors, and fly indoors to lay 30 to 100 eggs. Larvae are small, bristly, brown or striped, and molt several times over 6 to 12 months before pupating. They feed on keratin in wool, silk, fur, feathers, leather and pet hair, and can also eat dried food in pantries. Damage appears as irregular small holes in rugs and clothing, often in dark undisturbed places, and shed larval skins show infestation. Unlike clothes moth damage, there is usually no webbing. Carpet beetle larvae can cause small itchy red bumps on skin in sensitive people, but they do not bite or spread disease.
Control steps that work
Vacuum rugs, baseboards and closets thoroughly, then discard the bag outside. Wash fabrics at 120 F or above, or freeze items at 0 F for 72 hours. Store woolens in sealed containers, and reduce lint and pet hair buildup. Persistent infestations in walls or insulation may need a licensed pest control professional.
Based on data from university extension entomology programs and the EPA
