House moths eat either natural fabrics or stored food, depending on the species. The two most common types found indoors are clothes moths and pantry moths, and their larvae have completely different diets. Adult moths of both types have reduced or nonfunctional mouthparts and do not feed at all. Every bit of damage in your closet or kitchen is caused by the larvae.
Clothes Moths Feed on Animal-Based Fibers
Clothes moth larvae eat materials that contain keratin, the protein found in animal hair, skin, and feathers. That means wool, cashmere, silk, fur, feathers, and leather are all on the menu. They’ll also feed on items you might not think of: felt piano hammers, natural-bristle brushes, taxidermy mounts, wool rugs, and even dust that contains accumulated hair and skin cells in air ducts or baseboards.
The larvae can’t digest pure synthetic fibers like polyester or nylon. However, they will chew through synthetic and blended fabrics if those fabrics are stained with sweat, food spills, or body oils. The organic residue is what attracts them, and they’ll damage the surrounding synthetic fibers to get to it. This is why clothes that have been worn but not washed are at much higher risk than clean garments stored fresh from the laundry.
Two species account for nearly all clothes moth damage in homes: the webbing clothes moth and the casemaking clothes moth. Their larvae look almost identical and eat the same materials, but they leave different evidence behind.
How to Tell Which Clothes Moth You Have
Webbing clothes moth larvae spin patches of silk webbing as they feed, creating temporary tubes out of silk, excrement, and particles of the fabric they’re eating. When they move to a new feeding spot, they abandon these tubes and leave them behind. You’ll find them on hidden areas of garments, under collars, along seams, or on the underside of rugs.
Casemaking clothes moth larvae take a different approach. They build a portable silken case, roughly 3/8 inch long and cigar-shaped, and they never leave it. They feed from either end and retreat inside when disturbed. As they grow, they enlarge the case and incorporate fibers from whatever they’re eating, so the case takes on the color of the fabric. If you see a tiny tube the same shade as your wool sweater clinging to the surface, that’s your culprit.
Both species leave excrement that matches the color of the dyed fabric they’ve consumed. On fur, the telltale sign is hairs clipped at the base, leaving patches of loose fur and exposed hide. On woven fabrics, you’ll see surface grazing (thin spots where fibers have been eaten away) or irregular holes.
Pantry Moths Feed on Dried Foods
The other common house moth is the Indian meal moth, often called a pantry moth. Its larvae eat a remarkably wide range of stored food products: cereals, oatmeal, flour, nuts, dried fruits, spices, dried herbs, chocolate, candy, biscuits, powdered milk, dried soup mixes, and dried vegetables. They also readily infest pet food, including dry dog and cat food, flaked fish food, and bird seed. Even decorative items made from dried flowers or seeds can serve as breeding sites.
Pantry moth larvae spin silk webbing through the food they infest, which is often the first visible sign of a problem. You might notice fine, sticky threads clumping together cereal flakes or coating the surface of nuts. The larvae are small, pale caterpillars, and they can work through sealed cardboard boxes and thin plastic bags.
Spilled baking ingredients like flour in cabinet crevices or behind appliances can quietly sustain a pantry moth population even after you’ve thrown out obviously infested packages. Rodent seed caches hidden in walls or attics can also harbor them.
Telling the Two Types Apart
If you’re seeing moths flying around your home and aren’t sure which kind you have, a few quick observations can help. Clothes moths are small, only about 1/4 inch long at rest, and they have small tufts of hair on their heads. They flutter weakly and stay close to the area of infestation, rarely venturing far from the closet or drawer where larvae are feeding. You’re unlikely to see them flying around the kitchen.
Pantry moths are roughly twice the size. They fly in a more direct, steady pattern and are commonly seen flying around kitchens, pantries, and other rooms well away from their food source. If a moth is confidently cruising through your living room, it’s almost certainly a pantry moth, not a clothes moth.
What Adult Moths Do (and Don’t) Eat
Adult clothes moths do not eat. They have no functional mouthparts and cause no direct damage to fabrics. Their sole purpose as adults is to mate and lay eggs. The same is true for adult pantry moths. Every hole in your sweater and every silk strand in your cereal was produced by larvae, not the moths you see flying around. This matters because killing the visible adults without addressing eggs and larvae won’t solve an infestation.
Protecting Clothes and Food
For clothes moths, the single most effective step is cleaning garments before storing them. Larvae are drawn to fibers soiled with sweat, skin oils, and food residue, so laundering or dry cleaning removes both the attractant and any eggs already present. Store clean woolens and silks in airtight containers, sealed garment bags, or cedar-lined chests. Regularly vacuum closets, paying attention to corners, baseboards, and under furniture where lint and hair accumulate.
For pantry moths, inspect all dried goods when you bring them home. Transfer cereals, flour, nuts, spices, and pet food into hard-sided containers with tight lids, since larvae can chew through paper and thin plastic packaging. If you discover an infestation, discard all affected food, then thoroughly vacuum and wipe down shelves, paying special attention to cracks and corners where spilled food collects. Check less obvious sources too: dried flower arrangements, birdseed stored in the garage, and old bags of dog food.
Freezing is effective against both types. Placing infested items (or items you suspect may carry eggs) in a household freezer for at least 72 hours kills eggs, larvae, and adults. For valuable woolens or irreplaceable textiles, this is often the safest treatment option.