What Does Tineola Bisselliella Actually Eat?

Tineola bisselliella is the scientific name for the common webbing clothes moth. Despite the name, the adult moth does not eat fabric at all. It is the larval stage—the caterpillar—that causes the damage you see in your closet. These larvae feed primarily on keratin, a protein found in animal-based materials like wool, silk, fur, and feathers. They cannot digest synthetic fibers or plant-based cotton, though they may chew through them to reach a soiled spot on a garment.

What Does Tineola Bisselliella Actually Eat

The larvae of Tineola bisselliella eat keratin. Keratin is a tough, fibrous protein that makes up hair, wool, fur, feathers, and animal horns. It is the same protein in your own hair and fingernails. Most organisms cannot digest keratin, but clothes moth larvae have special enzymes in their gut that break it down.

This explains why a clean wool sweater in a sealed bag can remain untouched for years. The moth larvae need more than just the protein. They also require certain vitamins and minerals that are not present in clean, new wool. These nutrients are often found in sweat, urine, food stains, and skin cells that accumulate on worn clothing. This is why soiled garments are attacked before clean ones.

What Materials Are at Risk in Your Home

Clothes moths do not eat everything. Their diet is specific to animal-based proteins. Knowing which items are at risk helps you focus your protection efforts.

• Wool — sweaters, coats, blankets, carpets, and upholstery
• Silk — scarves, blouses, ties, and bedding
• Fur — coats, collars, and trim
• Feathers — down jackets, pillows, and comforters
• Cashmere and mohair — luxury knitwear
• Animal hair — items made from horsehair, alpaca, or angora
• Leather and suede — only when the surface is soiled, as moths cannot digest the tanned hide itself but will eat the oils and skin cells on the surface

Cotton, linen, and synthetic fabrics like polyester and nylon are not digestible. A moth may cut through a cotton shirt, but it does not do so for nutrition. It is usually tunneling toward a wool collar, a silk lining, or a stain containing skin cells or food residue.

Why Do Moths Damage Clothes They Cannot Eat?

You may find holes in a cotton t-shirt and assume the moth ate it. In most cases, the damage is not from feeding. The larvae crawl across fabric searching for a suitable food source. When they encounter a barrier, they cut through it with their mandibles. This creates irregular holes and frayed edges, but the material is not consumed.

Another reason for damage to non-keratin fabrics is the presence of stains. A cotton shirt with a food spill, body oil, or sweat mark becomes attractive because the stain itself contains digestible material. The larva eats the stain and cuts the surrounding fibers in the process. This is why laundered garments are far less vulnerable than unwashed ones.

How to Identify Clothes Moth Damage

Clothes moth damage looks different from carpet beetle damage, though both pests feed on keratin. Moth larvae leave behind silken webbing, which they spin as they move. You may see thin, web-like trails across the surface of a garment or in the corner of a drawer. They also leave behind fecal pellets that look like fine sand or tiny grains of pepper.

Carpet beetle larvae do not spin webbing. Instead, they leave shed skins and cause damage that appears more scattered and irregular. If you are unsure which pest you have, look for the adult insects. Webbing clothes moths are small, about a quarter of an inch long, and are a pale golden color. They avoid light and tend to hide in dark corners of closets or under furniture.

How to Prevent Infestations

Prevention focuses on removing the conditions that allow larvae to survive. The most effective steps are cleaning, storage, and monitoring.

Clean before storing. Wash or dry-clean all wool, silk, and fur items before putting them away for the season. This removes the sweat, skin cells, and food stains that attract moths. Dry cleaning also kills eggs and larvae.

Store properly. Use airtight containers, vacuum-sealed bags, or cedar chests with tight-fitting lids. Plastic bins and vacuum bags are more reliable than cedar because cedar oil loses its potency over time. Cedar alone does not reliably kill larvae, though it may deter adult moths from laying eggs.

Vacuum regularly. Pay attention to baseboards, under furniture, and the edges of carpets. Vacuuming removes hair, lint, and debris that could support a larval population. It also removes eggs and larvae before they become established.

Monitor with traps. Sticky pheromone traps attract adult male moths. They do not catch females, so they are not a control method. However, they are a useful early warning system. If you catch moths consistently, you have an active infestation and need to inspect your stored items.

How to Get Rid of an Active Infestation

An active infestation requires a thorough approach. Moth larvae can hide in cracks, under collars, and inside upholstery seams. Killing only the visible adults will not solve the problem.

Begin by removing and inspecting every vulnerable item in the affected area. Launder or dry-clean anything with visible damage or webbing. For items that cannot be washed, freezing is an option. Place the item in a sealed plastic bag and freeze it at 0°F or below for at least 72 hours. This kills eggs, larvae, and adults. Some experts recommend two freeze-thaw cycles to be certain, as eggs may survive a single cycle.

Heat is another option. Exposing items to temperatures above 120°F for at least 30 minutes kills all life stages. A clothes dryer on high heat can achieve this for washable items.

After treating the items, clean the space. Vacuum thoroughly, including under furniture and along baseboards. Discard the vacuum bag immediately in an outdoor trash container. Wash shelves and drawers with soap and water. Insecticides are available, but they should be used carefully and only in areas where food is not stored. Many pest control professionals recommend against routine chemical treatment of closets, as the risk to humans and pets often outweighs the benefit.

Do Mothballs and Cedar Actually Work?

Mothballs work, but they carry significant risks. The active ingredient in traditional mothballs is naphthalene or paradichlorobenzene. These chemicals vaporize into a gas that kills moths and larvae in an enclosed space. The gas is toxic to humans and pets with prolonged exposure. Mothballs must be used in airtight containers to be effective and safe. They should never be placed loosely in a closet or drawer, as the gas can spread through the home and cause respiratory irritation, headaches, and nausea.

Cedar is less effective than mothballs but safer. Cedar wood contains natural oils that repel adult moths. The effect is mild and diminishes as the oils evaporate. Cedar blocks and chips lose their potency over time, sometimes within months. Sanding the surface can release fresh oils, but the effect is temporary. Cedar may reduce the likelihood of infestation, but it will not kill an existing one.

Are Moths Harmful to Humans?

Clothes moths do not bite, sting, or transmit disease. They do not feed on human blood. The only harm they cause is economic—damage to clothing, carpets, and upholstery. Some people experience allergic reactions to moth scales, larvae, or their droppings, but this is uncommon.

The larvae themselves are harmless to touch, though they are small and may be difficult to see. If you find a larva on a garment, simply remove it and launder the item. There is no medical concern associated with handling clothes moths.