Clothes moths cause damage during their larval stage, not as flying adults, which means prevention is largely about making your closet and storage spaces inhospitable to eggs and larvae before an infestation takes hold. The good news: a combination of regular cleaning, proper storage, and monitoring can protect your wardrobe without resorting to toxic chemicals.
What Clothes Moths Actually Eat
Clothes moth larvae feed exclusively on animal fibers, especially wool, fur, silk, feathers, felt, and leather. These materials contain keratin, a protein that the larvae can digest. Cotton and synthetic fabrics like polyester and rayon are rarely attacked unless they’re blended with wool or heavily soiled with food stains or body oils.
That last detail is key to prevention. Perspiration, skin oils, and food spills act like a buffet sign for moths. A clean wool sweater is far less attractive than one worn a few times and tossed back on the shelf. Cleaning your garments before storing them removes both the scent that draws adult moths in and any eggs or larvae already present.
Clean Everything Before Storage
The single most effective step you can take is laundering or dry cleaning clothes before putting them away for the season. Washing in water at least 120°F for 20 to 30 minutes kills all life stages of clothes moths: eggs, larvae, and adults. A hot dryer cycle accomplishes the same thing. For delicate items that can’t handle heat, freezing works as an alternative. Place the garment in a sealed plastic bag and freeze it for at least 72 hours to kill hidden eggs and larvae.
Dry cleaning is another reliable option, particularly for structured garments like suits and coats that shouldn’t be machine washed. The point isn’t which method you choose. It’s that nothing goes into storage dirty.
Use Sealed, Moth-Proof Storage
Once your clothes are clean, the goal is keeping adult moths from reaching them to lay eggs. Regular plastic tubs and cardboard boxes aren’t airtight enough to reliably keep moths out. Purpose-made moth-proof storage bags, either fully airtight or breathable with durable zippers, offer much better protection. Vacuum-sealed bags work well too, with one caveat: make sure the garments are completely free of larvae and eggs before you seal them in, or you’ll just be locking the problem inside.
For items stored in attics, garages, or off-site storage units where you won’t check on them for months, moth-proof bags are especially important. These spaces are harder to monitor and more likely to harbor moths.
Cedar and Lavender: What They Can and Can’t Do
Cedar and lavender are the most popular natural moth deterrents, and they do work, but not the way most people assume. They don’t kill existing larvae. Instead, the volatile oils in cedarwood and lavender create what researchers call “olfactory noise,” masking the pheromones female moths release to attract males. This disrupts the breeding cycle and discourages egg-laying in treated areas.
The limitation is that these scents fade. Cedar balls need to be lightly sanded with fine sandpaper every three months or so to reopen the wood’s pores and release fresh oils. In humid climates, this needs to happen even more frequently. Lavender sachets fade faster still and should be gently squeezed every few weeks to crush the buds and release more oil. If your cedar blocks smell like nothing, they’re doing nothing.
Think of natural repellents as a supporting layer, not a standalone solution. They’re most effective when paired with clean garments in a well-sealed closet or storage bag, not when tossed into a pile of unwashed sweaters in an open bin.
Pheromone Traps for Monitoring
Sticky pheromone traps are a useful early warning system. They use a synthetic version of the female moth’s scent to lure male moths onto a glue surface. Placing one on the closet floor and one on a shelf gives you a good picture of whether moths are present and where they’re coming from.
These traps won’t solve an infestation on their own. They primarily catch males, and a single female that has already mated can lay enough eggs to keep the cycle going. What traps do well is tell you three things: whether moths are in your space, roughly where they’re concentrated, and whether your other prevention measures (cleaning, sealing, repellents) are actually working. If you cleaned everything and sealed your closet but the traps keep catching moths weeks later, you’ve missed a source.
Keep Closets Clean and Dry
Moths thrive in undisturbed, dark spaces with access to food sources. A closet that gets vacuumed regularly, with clothes that are rotated and worn, is a hostile environment for them. Pay attention to the corners and edges of closet floors, the crevices along baseboards, and any area where lint, pet hair, or dust collects. These accumulations of animal fiber are exactly what larvae feed on.
Humidity also plays a role. Moths prefer still, slightly damp air. Good ventilation in your closet, even just leaving the door open periodically, helps make the space less inviting. If you live in a humid climate, a small dehumidifier or moisture absorber in the closet is a worthwhile addition.
Why Mothballs Are a Last Resort
Traditional mothballs contain high concentrations of either naphthalene or paradichlorobenzene, both of which are classified as insecticides. They work by slowly releasing a toxic gas that kills moths and larvae. The critical detail most people miss: mothballs are designed to be used only in closed, airtight containers. The fumes need to build up to a lethal concentration to be effective, and that same concentration is harmful to people, pets, and wildlife.
Used out in the open, in a closet with gaps under the door, or scattered in a dresser drawer, mothballs release fumes into your living space without reaching concentrations high enough to reliably kill moths. You get the health risk without the benefit. If you have children or pets in the home, mothballs pose an additional poisoning risk if touched or eaten. For most people, the combination of laundering, sealed storage, natural repellents, and monitoring traps is both safer and more effective.
What to Do If You Already Have Moths
If you’re finding small holes in wool garments, seeing tiny cream-colored larvae, or catching adults on pheromone traps, act quickly. Start by inspecting every item made of animal fiber in the affected area. Launder or freeze anything that could be infested. Vacuum the closet thoroughly, including shelves, corners, and baseboards, and immediately dispose of the vacuum bag or empty the canister outside.
For items that can’t be washed or frozen, heating them in an oven at temperatures above 120°F for at least 30 minutes kills all life stages. This works for small items but obviously isn’t practical for a full wardrobe. Larger infestations, particularly ones that have spread to carpets, upholstered furniture, or multiple rooms, typically require professional treatment.
After cleaning, set up pheromone traps to monitor whether the population is declining. It can take several weeks to fully break the cycle, since eggs you missed may still hatch. Check traps weekly and re-inspect your garments after a month to confirm the problem is resolved.