Two species of moth are responsible for nearly all clothing damage in homes: the webbing clothes moth and the casemaking clothes moth. Both are small, pale, and easy to overlook. And in both cases, it’s not the adult moth chewing through your sweaters. The larvae do all the eating.
The Two Species That Damage Clothing
The webbing clothes moth is the more common of the two. Adults are golden-tan, about half an inch long, and have a distinctive habit of running along surfaces rather than flying toward lights. If you see a small moth fluttering around your lamp, it’s almost certainly not a clothes moth. Webbing clothes moths avoid light and prefer dark, undisturbed spaces like the back of a closet, a storage bin, or the underside of a rug.
The casemaking clothes moth is slightly less common but just as destructive. It looks similar but has faint dark spots on its wings. Its larvae build a small portable case out of silk and fiber fragments, dragging it along as they feed. Webbing moth larvae, by contrast, spin silky mats or tunnels directly on the fabric they’re eating. Both species can be found year-round in heated buildings.
Why Larvae Eat Your Clothes
Clothes moth larvae need keratin, a protein found in animal-based fibers. Wool, cashmere, silk, fur, feathers, and leather all contain keratin, making them prime targets. The larvae produce enzymes in their gut that break down this tough protein, something very few insects can do. This is why clothes moths are so specialized and why your wool coat is at risk while a polyester jacket sitting right next to it stays untouched.
Pure cotton and synthetic fabrics don’t contain keratin, so larvae can’t survive on them alone. However, blended fabrics that mix wool or silk with synthetic fibers can still be damaged. Larvae will chew through synthetic threads to reach the animal fibers woven alongside them. Clothes soiled with sweat, food stains, or body oils are especially attractive because those residues provide additional nutrients. A clean wool sweater stored properly is far less appealing than one stuffed into a bin after being worn.
How the Life Cycle Works
A single female clothes moth lays 40 to 50 eggs over a period of several weeks. Those eggs hatch in 4 to 10 days, releasing tiny larvae that immediately begin feeding. The larval stage, the only stage that causes damage, lasts about 67 days under favorable conditions. But if food is scarce or temperatures are cool, larvae can survive and keep feeding for up to 29 months. That’s over two years of slow, steady destruction happening silently inside a storage box.
After the larval stage, pupation takes anywhere from 8 to 44 days before an adult moth emerges. Adult males live about 28 days, females about 16. Adults don’t eat at all. Their sole purpose is to mate and lay eggs, starting the cycle over again. Because the entire life cycle can happen in a dark closet or attic, infestations often go unnoticed until significant damage has already occurred.
Larvae become inactive below 40°F, which is why clothes moth problems are far worse in heated homes than in uninsulated sheds or garages. Warm, humid, undisturbed environments are ideal for them.
Signs of an Infestation
The damage itself is the most obvious sign: irregular holes in wool garments, thinning patches on rugs, or bare spots on furs. But there are earlier clues if you know what to look for. Webbing clothes moth larvae leave behind silky webbing on fabric surfaces, sometimes forming small tunnels or mats. Casemaking moth larvae leave their tiny cigar-shaped cases, often the same color as the fabric they’ve been eating because the cases are built from fiber fragments.
You may also find tiny sand-grain-sized droppings (frass) near damaged items, or shed larval skins. The larvae themselves are small, creamy-white caterpillars, typically less than half an inch long. They tend to stay on the underside of fabrics or in folds and seams where they’re protected from light and disturbance. If you spot a small golden moth walking along your closet shelf, check nearby woolens carefully.
Which Items Are Most at Risk
Anything containing animal fibers stored in a dark, undisturbed spot is vulnerable. The highest-risk items include wool suits and sweaters, cashmere scarves, silk blouses, fur coats, feather pillows, and wool rugs or tapestries. Upholstered furniture with wool padding can also be targeted, particularly underneath or along the back where nobody looks.
Items you wear regularly are at lower risk because the physical movement and light exposure disrupt larvae. The real danger zone is seasonal storage: winter coats packed away for summer, heirloom blankets in attic boxes, or formal wear that hangs untouched for months. The longer something sits undisturbed, the more time larvae have to complete their feeding cycle.
How to Kill Clothes Moths at Every Stage
Heat and cold are the most reliable weapons. Laundering infested items in water at 120°F or higher for 20 to 30 minutes kills eggs, larvae, and adults. A clothes dryer on a hot setting achieves the same result. For items that can’t be washed, dry cleaning is equally effective.
Freezing works too, but requires patience. Seal the infested item in a plastic bag and place it in a freezer at 0°F or below for at least one week. Freezers that reach minus 20°F can kill all life stages within 72 hours. The key is ensuring the cold penetrates the entire item, so don’t overstuff the freezer or stack bags tightly together.
For items that can’t be laundered or frozen, you can place them in an oven at temperatures above 120°F for at least 30 minutes, though this only works for items that can tolerate heat without damage.
Preventing Reinfestation
The best prevention is removing the conditions larvae need. Clean all garments before storing them, since body oils, sweat, and food residue make fabrics more attractive to egg-laying females. Store clean woolens in airtight containers or sealed garment bags. Cedar chests and cedar blocks have a mild repellent effect on young larvae, but they won’t kill an established infestation.
Pheromone traps, available at most hardware stores, use a sticky surface laced with synthetic female moth scent to capture adult males. These traps are useful for monitoring whether you have a problem, but they won’t eliminate an infestation on their own because they only catch males and don’t affect larvae or eggs.
Regular vacuuming along closet edges, baseboards, and under furniture removes stray eggs and larvae before they can establish themselves. Pay special attention to corners and crevices where lint, hair, and pet fur accumulate, since these organic materials can sustain larvae even without a wool garment nearby.