Life's Little Mysteries

Why Do Moths Eat Clothes?

It may be gross enough to discover that moths have eaten a hole through your favorite cashmere sweater, but get this -- it's not actually the moths that eat your clothes, but their slimy larvae.

Simply put, it's impossible for adult moths to eat your threads. Moths only have mouths during their larval, or caterpillar, stage, which usually lasts from when the insect is about two weeks old until it turns a month.

Here's how the little buggers get there. First, a female moth deposits a mass of fertilized eggs -- which can range from 50 to 1,000 eggs -- onto a piece of clothing that she's deemed fitting for her offspring.

Moth larvae have a fairly specific diet, and so female moths typically pick clothes made from animal fibers such as silk, wool, cashmere, angora or fur, materials that contain keratin. Keratin is composed of fibrous structural proteins and can also be found in our skin and hair . Moth caterpillars will sometimes eat leather and feathers -- and yes, even lint and hairballs of human or pet hair.

Thankfully, moth larvae avoid eating synthetic and cotton fabrics unless they're blended with an animal fiber. That's because synthetic and cotton material doesn't contain keratin . So at least your spandex is safe.

The larvae of the clothes moth (Tineola bisselliella), also known as the webbing clothes moth, are the most common clothing destroyers. Unlike most moths , clothing moths hate light and prefer to hide away in the dark depths of closets, where they can discreetly deposit their larvae onto the nearest suitable garment.

Follow Remy Melina on Twitter @RemyMelina

Remy Melina was a staff writer for Live Science from 2010 to 2012. She holds a bachelor’s degree in Communication from Hofstra University where she graduated with honors.