The small, silken cases or cocoons you’re finding in your home almost certainly belong to clothes moths, the most common fabric-damaging moths in houses. Two species are responsible for nearly all indoor infestations: the webbing clothes moth and the casemaking clothes moth. Each produces a distinctly different type of cocoon, and knowing which one you’re looking at helps you figure out how far the infestation has spread and where to focus your cleanup.
What House Moth Cocoons Look Like
The two common clothes moth species leave behind very different evidence, so the cocoon you’ve found will point to which one you’re dealing with.
Casemaking Clothes Moth
Larvae of the casemaking clothes moth build a portable silken case that they carry with them everywhere they feed. They never leave it behind. As the larva grows, it enlarges the case, feeding from either end and retreating inside when disturbed. A fully grown larva’s case is cigar-shaped, open at both ends, and roughly 3/8 inch long. Bits of the fabric the larva has been eating get woven into the silk, so the case takes on the color of whatever material it’s been consuming. A case found on a blue wool sweater will look bluish; one on a beige carpet will blend right in. This camouflage is one reason they’re easy to miss.
If you find one of these cases attached to a piece of fabric at one end, it likely still contains a live larva or pupa. Gently nudge it: a larva will retract deeper inside.
Webbing Clothes Moth
Webbing clothes moth larvae don’t carry portable cases. Instead, they spin patches of silk webbing directly on the fabric they’re eating, creating temporary feeding tubes that accumulate droppings and tiny particles of the material. When they move to a new feeding spot, they leave these messy tubes behind, so you may find irregular trails of silk and debris on clothing or carpet even after the larvae have moved on.
When a webbing clothes moth larva is ready to pupate, it spins a silken cocoon, typically right on the fabric it’s been feeding on. This cocoon is the structure that many people find and search for online. It’s a small, somewhat flattened silk pouch, often incorporating fiber fragments from the surrounding material. Because it sits on the fabric surface rather than being carried around, you’ll usually spot it in a fold of a garment, along a carpet edge, or tucked against a seam.
Where to Look for Cocoons
Clothes moth cocoons and cases turn up in the same places the larvae feed: dark, undisturbed spots with access to animal-based fibers. Wool sweaters folded at the back of a closet shelf, stored blankets, fur items, and feather-filled pillows are prime targets. Carpet edges along baseboards, especially under heavy furniture that rarely gets moved, are another common hiding spot. The larvae prefer areas that stay dark and quiet for long stretches, so the guest room closet you open twice a year is higher risk than the coat closet you use daily.
Don’t overlook less obvious sources of animal fiber. Felt pads under furniture legs, wool-blend upholstery on the underside of chairs, taxidermy, old wool insulation in attics, and even accumulations of pet hair and lint in floor vents can all support a colony. If you’re finding adult moths (small, gold or buff-colored, about 1/2 inch long) fluttering weakly near walls, the cocoons are likely within a few feet of where you see them. Adults are poor fliers and tend to stay close to where they emerged.
How to Tell If a Cocoon Is Active
An empty cocoon or abandoned case means the moth has already emerged, but it also confirms an active or recent infestation in that area. For casemaking moth cases, check whether the case is firmly attached at one end and feels slightly heavier than an empty shell. An active case may show the larva peeking from one opening. For webbing moth cocoons, a sealed cocoon that hasn’t been torn open likely still contains a developing pupa. If you see a small hole at one end, the adult moth has already exited.
Even empty cocoons are worth taking seriously. A single female moth can lay 40 to 50 eggs, and multiple generations can overlap indoors where temperatures stay comfortable year-round. Finding old cocoons means the population has been cycling in your home, and eggs or young larvae you can’t yet see are likely nearby.
How to Get Rid of Them
Eliminating moth cocoons requires a combination of physical removal, cleaning, and temperature treatment. No single step is enough on its own because eggs, larvae, and pupae can all be present simultaneously in different locations.
Vacuum thoroughly. Go over every surface in the affected area, paying special attention to carpet edges, closet floors, shelf corners, and crevices along baseboards. Use a crevice attachment to reach into folds of stored textiles. Vacuuming physically removes cocoons, cases, larvae, and eggs. Empty the vacuum bag or canister into an outdoor trash bin immediately afterward so nothing hatches inside.
Wash or dry-clean affected fabrics. Hot water washing kills all life stages. For items that can’t be washed in hot water, dry cleaning is effective because the solvents are lethal to moths at every stage. Even a normal warm-water wash with detergent will dislodge and destroy most eggs and young larvae.
Use temperature extremes. Freezing is practical for delicate items like wool garments, furs, or feather pillows. Place the item in a sealed plastic bag and freeze it for at least 72 hours at 0°F (-18°C) or below, which is the setting of most home freezers. For heat treatment, a household dryer on high heat for 30 minutes will kill all stages. Items too large for a dryer or freezer, like rugs, can be taken to a professional cleaner or left in direct sunlight on a very hot day, though professional treatment is more reliable.
Clean storage areas before restocking. Wipe down closet shelves, drawer interiors, and storage bins with a damp cloth to pick up any remaining eggs. Moth eggs are tiny (smaller than a pinhead) and stick to surfaces, so a quick wipe is more effective than dusting alone.
Preventing New Cocoons From Appearing
The single most effective prevention step is proper storage. Clean garments before putting them away for the season, because clothes moths are especially attracted to fabrics that carry sweat, body oils, or food stains. Store clean woolens, silks, and furs in sealed plastic bags, airtight bins, or garment bags with zippers. Cedar blocks and lavender sachets may offer a mild deterrent, but they won’t kill an active infestation or stop determined females from laying eggs.
Regular disturbance matters more than most people realize. Simply taking stored items out, shaking them, and refolding them a few times a year can discourage moths from settling in. Vacuuming closet floors and carpet edges monthly removes the hair, lint, and fiber debris that larvae feed on before they ever reach your good sweaters. Keeping storage areas well-lit and ventilated also helps, since clothes moths strongly prefer dark, still environments.
Sticky pheromone traps designed for clothes moths are useful as a monitoring tool. They attract adult males and can alert you to an infestation before you notice fabric damage. They won’t eliminate an existing population on their own, but a sudden spike in trapped moths tells you it’s time to inspect stored textiles and clean the area thoroughly.