The idea that clothes moths exclusively target wool is a common but incomplete understanding of their diet. These insects, primarily members of the Tineidae family, have a biological requirement that dictates their consumption. Understanding what truly attracts these pests is the first step in protecting textiles. The moth’s destructive behavior is driven by a unique ability to process a protein found in a wide variety of materials, making the threat far broader than just woolen garments.
The Real Food Source of Clothes Moths
The actual target of the clothes moth is not the fiber itself but the complex protein called keratin. Keratin is the structural material that makes up animal hair, fur, feathers, and skin, and it is abundant in materials like wool, cashmere, mohair, silk, and alpaca. Clothes moth larvae are among the few organisms that possess the biochemical machinery to break down this durable protein. This capability is attributed to specialized enzymes, known as keratinases, which may be secreted by symbiotic bacteria living within the larval gut.
This need for animal protein explains why clothes moths attack a broad range of natural materials, including leather, felt, and hair or bristle brushes. Purely synthetic fibers like polyester, nylon, or acrylic are safe because they contain no keratin. However, even synthetic or plant-based materials like cotton can become targets if they are soiled with organic residues, such as food stains, perspiration, or body oils. These residues provide the larvae with moisture and supplemental nutrients, making the soiled garment an attractive place for the female moth to lay her eggs.
The Destructive Stage of the Moth Life Cycle
A common misconception is that the fluttering adult moth is responsible for creating holes in fabric. The adult clothes moth, once emerged, does not feed at all; its functions are limited to mating and dispersal. Adults of certain clothes moth species often lack functional mouthparts entirely, making it impossible for them to consume textiles. The adults live only long enough to reproduce, with females laying up to 50 eggs directly onto a suitable food source before dying.
It is the larval, or caterpillar, stage that causes all the destruction to clothing and textiles. Once hatched, the tiny, cream-colored larva begins to feed voraciously on the surrounding keratin to fuel its growth. This feeding stage can last anywhere from a month to two years, depending on the availability of food, temperature, and humidity. The larvae are often found in dark, undisturbed areas, where they graze on the fibers, sometimes spinning silken tubes or leaving behind fine webbing as they move.
Protecting Textiles and Preventing Infestation
Preventing an infestation begins with understanding the specific signs of larval activity, which go beyond finding irregular holes in fabric. Larvae often leave behind silken webbing or casings, as well as small, sand-like fecal pellets called frass, concentrated near the damage site. Shed larval skins, which are tiny and translucent, can also indicate a developing problem.
A foundational preventative measure is to clean garments before placing them in long-term storage, as even invisible traces of human residue attract the pests. For affected items, laundering in water that is at least 120°F for 20 to 30 minutes kills eggs and larvae. Non-washable items can be dry-cleaned or subjected to cold treatment by placing them in a sealed bag in a freezer for at least 72 hours.
Long-term storage should utilize airtight plastic containers with secure lids, as clothes moths can easily penetrate cardboard and fabric bags. Regularly vacuuming all storage areas, especially cracks, crevices, and along baseboards, removes residual eggs, larvae, or shed hair. Pheromone traps can also be used to monitor for the presence of adult male moths, offering an early warning of an infestation.