The discovery of unexplained holes in textiles is a common household problem. The damage is almost never caused by the adult insect; instead, it is the larvae, the immature stage of the pest, that consumes the fibers. These tiny, often unseen, larvae systematically destroy natural fabrics like wool, silk, and fur. Understanding the specific culprits and their feeding habits is the first step toward effective mitigation and long-term protection of stored items.
The Primary Culprits
The vast majority of fabric damage is attributed to two main groups of pests: clothes moths and carpet beetles. Clothes moths, such as the webbing and casemaking clothes moths, are tiny, golden-buff insects that avoid light, meaning the adults are rarely seen flying openly. The larvae are small, creamy-white caterpillars, about a half-inch long, and are the only stage that feeds on textiles. The adult female clothes moth lays hundreds of eggs directly on a suitable food source for her offspring.
Carpet beetles are another significant threat, including species like the varied, furniture, and black carpet beetles. Adult carpet beetles are small, oval-shaped insects, often found near windowsills after emerging from their pupal stage. The larvae, sometimes called “woolly bears,” are bristly and brownish, typically measuring less than a quarter-inch long. Unlike moth larvae, carpet beetle larvae tend to wander from the feeding source, spreading the infestation widely. A third, lesser culprit is the silverfish, a wingless insect that chews through fabric, usually only to access starches and adhesives.
Understanding the Attractants
These insects target natural fibers because they possess the biological machinery to digest keratin, a complex protein. Keratin is the primary structural component of hair, feathers, fur, and wool, making these materials highly nutritious for the larvae. The larvae’s digestive tract contains specialized enzymes, primarily serine proteases, which break down the keratin protein. This adaptation means that textiles made from animal-based materials—including cashmere, alpaca, and silk—are vulnerable to attack.
The larvae are also strongly attracted to textiles soiled with organic contaminants. Stains from sweat, body oils, urine, and food spills provide supplementary nutrition that accelerates larval growth. Even on synthetic or plant-based fabrics like cotton and linen, these spills can draw pests, who will chew through the material to reach the stain. Therefore, clean clothing is significantly less appealing than soiled items, regardless of the fiber type.
Recognizing Distinct Damage Types
Identifying the culprit depends on recognizing the specific evidence left behind. Clothes moth larvae typically create irregular, scattered holes in garments, often accompanied by fine, silken webbing or tunnels. For the webbing clothes moth, this silk is used to construct tubes for movement and feeding. Fine, sand-like fecal pellets, called frass, are frequently found tangled within the silk, and damage tends to be concentrated in dark, undisturbed areas like under collars or within fabric folds.
Carpet beetle damage usually appears as smaller, more numerous holes that look like grazing, as the larvae often chew the nap off the fabric surface. The most definitive sign of a carpet beetle problem is the presence of numerous, brown, bristly, shed larval skins. These cast skins are cigar-shaped and found near the damaged textile, along with gritty, sand-like frass matching the color of the material consumed. Unlike moths, carpet beetles do not spin webbing.
Effective Eradication and Prevention
Eradicating an active infestation requires immediate treatment of all affected items to kill every life stage—egg, larva, and adult. Infested clothing can be professionally dry cleaned, as the solvents are lethal to the pests. For washable items, washing in hot water, specifically a cycle reaching at least 120 degrees F for 20 to 30 minutes, is effective. Alternatively, freezing the infested items is a simple method, requiring textiles to be sealed in plastic bags and placed in a freezer at 0 degrees F for a minimum of 48 to 72 hours.
Environmental Control
After treating the items, prevention focuses on environmental control and proper storage practices. Thorough vacuuming is necessary to remove eggs and larvae from all areas, especially around baseboards, under furniture, and in seldom-used storage spaces. Pet hair and lint, which serve as food sources, must be regularly removed from the home.
Storage Practices
For long-term storage, store only clean garments in sealed, airtight containers or garment bags. While cedar chests and mothballs are popular, they offer limited protection. The volatile oils in cedar lose their efficacy over a couple of years, and mothballs must reach a high concentration of vapor in an airtight space to be lethal. Pheromone traps can be placed in closets to monitor for the presence of adult male moths, signaling a potential infestation and allowing for early intervention.