Clothes moths are small, beige moths whose larvae eat keratin, the protein in wool, cashmere, fur and feathers, and they attack silk too. The larvae do the damage, not the adults, and they go first for wool that is soiled and left undisturbed in the dark, such as a blanket stored all summer at the back of a closet. To keep them out, store wool clean and completely dry in sealed containers, and use, air and check your blankets regularly.
If moths have already moved in: isolate everything made of wool nearby, brush and shake it out outdoors, kill eggs and larvae by freezing small items in a sealed bag for several days or by professional cleaning, vacuum the closet thoroughly, and watch for new moths with pheromone traps. Cedar and lavender may deter adult moths, but they do not kill larvae.
What clothes moths are and what they eat
Two species do most of the damage in homes: the webbing clothes moth and the casemaking clothes moth. The adults are about 1/4 inch (6–7 mm) long, golden to brownish beige, and they avoid light. You are more likely to see one flutter out of a closet or scurry into a fold than circle a lamp. A moth circling the kitchen light is usually a pantry moth, a different pest.
The adults don't eat at all. Their larvae, creamy-white caterpillars with a darker head and up to about 1/2 inch (13 mm) long, feed mainly on keratin. That puts wool blankets, merino and cashmere sweaters, felt, down pillows and fur on the menu, and silk is at risk as well. Cotton and synthetics are rarely eaten unless they are soiled or blended with wool, and in a blend the larvae go for the wool.
Soiled wool attracts them most. Sweat, skin oils and food or drink spills give the larvae nutrients and moisture that clean wool lacks. And they like to be left alone: dark, quiet places where nothing is moved for months.
Signs of clothes moths
- Irregular holes, often in folds, along edges or in parts that stay hidden
- Thin, grazed patches where surface fibers have been eaten
- Silky webbing or small tunnels on the fabric, sometimes with fibers and droppings stuck to them
- Small, flat cases the color of the fabric, attached to it or to the closet wall
- Tiny, grain-like droppings, often the same color as the wool that was eaten
- Small beige moths that flutter away from the light when you open a closet or drawer
Look in the hidden places first: the folds of stored blankets, the underside of rugs, the back of closet shelves and the floor under furniture.
How to prevent clothes moths in wool blankets
- Clean before you store. Wool used all winter carries skin oils and crumbs that attract larvae. Wash washable woolens as their label allows. Our wool and merino throws, including the cashmere blend with 10% cashmere, say do not wash on the label: air and brush them, and have them dry cleaned if they have seen a lot of use. Our guide on how to wash a wool blanket covers both routes.
- Make sure it is completely dry. Wool packed away damp turns musty.
- Store it airtight. A plastic bin with a tight-fitting lid or a sealed storage bag keeps adult moths from laying eggs on the wool. A cotton bag keeps dust off, but it is only as tight as its closure.
- Keep storage cool and dry, not in a damp basement or a hot attic.
- Air and check stored wool a few times a season: unfold it, shake it out outdoors and look along the folds.
- Use your blankets. A throw that is used, shaken and moved around every week is much less likely to be eaten, because larvae need to be left undisturbed.
- Vacuum closets and corners regularly, including baseboards, shelf edges and the floor under furniture, where fluff and eggs collect.
How to get rid of clothes moths
- Find and isolate. Take everything made of wool, silk, fur or feathers out of the affected closet or chest and check it piece by piece. Seal anything with damage or larvae in plastic bags so the moths can't spread.
- Brush and shake outdoors. Brush both sides of each blanket firmly, especially folds, seams and fringes, to knock off eggs and larvae, and shake it out well away from the house.
- Freeze small items. Seal a small blanket or throw in a plastic bag, press out the air and put it in a freezer at 0 °F (−18 °C) or colder for several days; a week is a common rule of thumb. Let it thaw inside the sealed bag, so condensation forms on the plastic and not on the wool.
- Have larger items dry cleaned. Professional dry cleaning kills eggs and larvae, and it is the practical route for a blanket that won't fit in your freezer. A cold wool wash can't be relied on to do the same.
- Clean the closet. Vacuum shelves, corners, cracks, baseboards and the floor, then wipe the surfaces down. Empty the vacuum outdoors and throw the contents away in a sealed bag.
- Keep watching. Set a pheromone trap in the closet to see if moths are still active. Eggs you missed can hatch days or weeks later, so check stored wool again after a month.
- Call a pest control professional if moths keep coming back. The source is often somewhere you haven't looked: an old rug, a wool-stuffed chair, a forgotten box of sweaters. If you use an insecticide or moth repellent yourself, follow its label exactly.
Traps, cedar and lavender: what they can and can't do
| Method | What it does | What it doesn't do |
|---|---|---|
| Pheromone traps | Lure and catch male moths of the species they are made for, so you can see if moths are active and where | Catch females or larvae, or end an infestation on their own |
| Cedar blocks or a cedar chest | May deter adult moths while the scent is strong; sand the wood lightly each season to refresh it | Kill larvae already in the wool |
| Lavender sachets | May deter adult moths while the scent lasts | Kill eggs or larvae |
| Freezing | Kills eggs and larvae in small items sealed in a bag | Protect the item from new moths afterward |
| Dry cleaning | Kills eggs and larvae and removes the soil that attracts them | Protect the item from new moths afterward |
| Airtight storage | Keeps moths away from clean wool | Help if eggs were already on the wool when it went in |
In short, traps tell you whether moths are around, and scents may keep some away. Cleaning or freezing is what kills them in wool, and sealed storage keeps them out.
FAQ
Do clothes moths eat merino wool?
Yes. Merino is wool, and wool is exactly what the larvae eat. Blends are not immune either: in our 80% merino, 20% nylon throws, the merino is food, so the same storage rules apply.
How long do you freeze a blanket to kill moth larvae?
Several days at 0 °F (−18 °C) or colder, sealed in a bag; a week is a common rule of thumb. Let it thaw in the bag before you open it.
Do mothballs work against clothes moths?
Mothballs are a pesticide. They only work in a closed space where the fumes build up, and their smell clings to wool. If you use them, follow the label exactly. For blankets, clean, sealed storage and regular checks are usually enough.
Can moth holes in a blanket be repaired?
Small holes can be darned, and a professional reweaver can mend holes in a woven blanket. Clean the blanket first so no eggs are left.
