Brown clothes moth larvae are small, cream-colored caterpillars that feed on wool, silk, fur, and other animal-based fabrics in your home. They’re the life stage that causes all the damage. Adult moths don’t eat fabric at all. If you’ve found tiny worm-like creatures in your closet, holes in a stored sweater, or silken tubes clinging to a rug, larvae are almost certainly responsible.
What the Larvae Look Like
Clothes moth larvae are cream to yellowish-white, soft-bodied, and less than half an inch long when fully grown. They have a darker head capsule, which helps distinguish them from the pale fabric around them. Two species cause most household damage, and their larvae behave differently in ways that help with identification.
Casemaking clothes moth larvae spin a portable protective case around themselves, incorporating tiny pieces of whatever fabric they’re eating. They drag this case along as they feed, and it eventually hardens into a tough cocoon for pupation. If you spot what looks like a small, fabric-colored tube slowly moving across a garment, that’s a casemaking larva inside its shelter.
Webbing clothes moth larvae take a different approach. Instead of building a portable case, they spin silken feeding tubes and attach them directly to the item they’re eating. You may notice a web-like layer of silk on the surface of a wool blanket or rug, sometimes matted with fibers and tiny fecal pellets. The larvae stay within or near these tubes while they feed.
What They Eat and Why
Clothes moth larvae feed exclusively on animal fibers: wool, fur, silk, feathers, felt, and leather. These materials contain keratin, a fibrous protein that the larvae can digest thanks to specialized enzymes most insects lack. In nature, they fill an ecological niche by breaking down the nesting materials and carcasses of birds and mammals. Inside your home, they target the same proteins in your belongings.
Commonly infested items include sweaters, scarves, coats, blankets, rugs, down pillows and comforters, upholstered furniture, stuffed toys, decorative items, and taxidermy mounts. Cotton and synthetic fabrics like polyester and rayon are rarely attacked unless they’re blended with wool or heavily soiled with food stains and body oils. Soiling matters because the larvae are attracted to the salts, oils, and proteins left behind by human skin and spilled food.
Larvae also feed on lint, shed pet hair, and other bits of debris that accumulate in undisturbed corners, under furniture, and along baseboards. Bird nests or animal carcasses in attics, chimneys, or wall cavities can serve as a hidden breeding ground that seeds infestations throughout the rest of the house.
How Long the Larval Stage Lasts
The larval stage is by far the longest part of a clothes moth’s life cycle, and its duration varies widely depending on temperature, humidity, and food quality. Under typical indoor conditions, larvae feed for several weeks to several months. In cooler environments or when food is scarce, the larval stage can stretch beyond a year. This extended feeding period is why damage can be so extensive before you even notice a problem, especially in items stored in closets, attics, or bins that go unopened for months.
Warmer, more humid conditions speed development. A home kept at comfortable room temperature with moderate humidity provides near-ideal conditions for larvae to grow quickly and produce multiple generations per year.
Telling Moth Larvae From Carpet Beetles
Carpet beetle larvae cause similar damage to the same types of fabrics, so it’s worth knowing the differences. Carpet beetle larvae are about one-eighth to one-quarter inch long and covered in tiny hairs or bristles, giving them a fuzzy or striped appearance. They do not spin webs or make cocoons. As they grow, they shed their skins, and these cast skins can look deceptively like living larvae, making an infestation seem larger than it is. Carpet beetle larvae also leave behind small fecal pellets near feeding sites.
If you see silken tubes, webbing, or portable cases on the damaged fabric, you’re dealing with clothes moths. If you see bristly, hairy larvae with no silk at all, carpet beetles are the culprit. The distinction matters because some control strategies differ between the two.
Killing Larvae With Heat and Cold
Temperature is one of the most reliable ways to kill clothes moth larvae at every life stage, including eggs. Laundering infested items in water at least 120°F for 20 to 30 minutes is the most common and effective method. For items that can’t handle hot water (which includes many wool garments), dry cleaning achieves the same result.
You can also heat items in an oven at temperatures above 120°F for at least 30 minutes. Freezing works too: seal the item in an airtight plastic bag and place it in a freezer set below 18°F for several days. The bag prevents moisture damage during thawing. Some sources recommend cycling between freezing and room temperature to ensure all eggs are killed, since eggs can sometimes survive a single freeze cycle.
Chemical Treatment Options
For items that can’t be laundered, dry cleaned, heated, or frozen, insecticide sprays labeled for clothes moths are an option. These products typically contain either pyrethrins or permethrin, and the two work differently.
Pyrethrin-based sprays deliver a fast knockdown and can be applied directly to fabrics in most cases. They don’t leave a long-lasting toxic residue, which makes them a better fit when you need to treat clothing or bedding you’ll be using again soon. Permethrin-based products, on the other hand, leave a residual layer that continues killing insects over time. These are best applied along baseboards, closet edges, carpet margins, under furniture, and in storage areas rather than directly on garments you wear.
Mothballs and moth crystals containing naphthalene or paradichlorobenzene are another option for long-term storage. They only work in airtight containers where the fumes can build to lethal concentrations. If the container isn’t airtight, layer paper every few inches and place the moth repellent on the paper. Keep these chemicals away from plastic buttons, hangers, and garment bags, because they can soften plastic and cause it to melt into the fabric.
Preventing Reinfestation
Larvae thrive in undisturbed, dark spaces. Regular vacuuming along baseboards, under furniture, inside closets, and in corners removes the lint, pet hair, and debris that sustain small populations. Pay special attention to areas where pet hair collects, since it’s a keratin-rich food source larvae readily consume.
Before storing wool, silk, or fur items for the season, clean them thoroughly. Even invisible body oils and food residues attract larvae, and a freshly cleaned garment stored in a sealed container is far less appealing. Airtight plastic bins or vacuum-sealed bags physically prevent adult moths from reaching fabrics to lay eggs.
Pheromone traps sold for clothes moths attract adult males using synthetic sex pheromones. They’re useful as a monitoring tool to detect an infestation early or confirm one is resolved, but they don’t kill larvae or females. Traps alone won’t eliminate an active infestation. They work best as an early warning system alongside cleaning and proper storage.
Check attics, chimneys, and wall cavities for old bird nests or animal remains. These hidden reservoirs can continuously produce new moths that spread to the rest of the house, making indoor control efforts feel futile until the source is removed.