You pull a wool sweater out of the closet and it is full of holes. Or you find small brown, hairy larvae under the bed, with empty skins nearby. Two likely culprits: the clothes moth and the carpet beetle. Their larvae eat the same thing, the keratin in animal fibres, but they hide in different places. Telling them apart helps you find the source, and the source is the whole problem.
Clothes moth or carpet beetle?
| Clothes moth | Carpet beetle (varied carpet beetle) | |
|---|---|---|
| Adult | Small moth, 6 to 7 mm, plain golden | Round beetle, 2 to 3 mm, mottled white, brown and yellow |
| Adult behaviour | Avoids light, flutters in closets | Heads for light: windowsills in spring, flowers |
| Larva | White caterpillar spinning a case or silk threads | Brown, hairy, banded larva, 4 to 5 mm, leaves empty skins |
| Damage | Clean holes, often under silk | Irregular holes, grazed surfaces, rug pile cut |
The black carpet beetle is another common one: the adult is black and oval, the larva long and golden brown with a tuft of hairs at the tail.
The small grey and copper moths flying in the kitchen are something else: pantry moths.
What they eat
The larvae digest keratin: wool, cashmere, alpaca, silk, fur, feathers, felt, poorly tanned leather. They prefer soiled fibres: sweat, food or urine stains. Carpet beetles also eat pet hair, rug lint and dead insects.
That is often where the real source hides: an abandoned bird’s nest, a dead rodent, or hundreds of dead Asian lady beetles and cluster flies in the attic or walls. Carpet beetles breed there, then make their way down into the rooms.
Where to look
- Closets and wardrobes: wool clothing stored for a long time, coats, scarves.
- Under and behind furniture, under the bed, along rug edges, where the vacuum doesn’t reach.
- Wool rugs, especially under heavy furniture.
- Heating and ventilation registers.
- The attic, windowsills, bird nests near the roof.
How to get rid of them
1. Sort and treat the clothes
- Wash in hot water whatever can take it, or have it dry-cleaned.
- For delicate items: seal in a plastic bag and freeze at −20 °C for one week, as recommended by the Canadian Conservation Institute. Let it return to room temperature in the sealed bag, so condensation forms on the bag and not on the fabric.
- Throw out what is too damaged.
2. Clean thoroughly
- Vacuum everywhere: rug edges, baseboards, under furniture, inside closets, vents. Throw the bag out outside.
- Clean wool rugs on both sides.
3. Store so it doesn’t happen again
- Only store clean clothes.
- Airtight bags or bins for off-season woollens.
- Cedar and lavender have a weak, short-lived effect: they don’t replace cleaning or sealed containers.
4. Monitor
Pheromone traps for clothes moths catch males and show whether the infestation is ongoing. They don’t attract carpet beetles; for those, sticky traps near windows and baseboards give a sense of activity.
When to call
- New holes keep appearing after the big clean-up.
- You find carpet beetle larvae in several rooms: the source is probably in a wall, ceiling or the attic.
- You had a lady beetle or cluster fly invasion in the fall, and carpet beetles show up in spring.
- You own valuable rugs, furs or textiles.
A technician finds the source, treats rug edges, closets and the voids involved, and tells you what to fix. See also our guide to bugs in the house. For an assessment, contact us or call 514-638-8705.
Frequently asked questions
Do carpet beetles bite?
No. But the larvae’s hairs can irritate some people’s skin, which is sometimes mistaken for bed bug bites.
Do moths eat cotton and polyester?
Not as food: they only digest keratin. They may damage a blended or stained fabric to get at what they want.
Why are there small beetles at the windows in spring?
Adult carpet beetles head for the light to get outside and feed on pollen. Seeing them at the windows means larvae developed inside the house over the winter.