Moth Larvae Damage: What They Eat and Where They Hide

Nobody ever caught a clothes moth larva in the act. They are small, pale and they feed out of sight, which is exactly why they cause so much damage before anyone notices.

Understanding their diet makes it much easier to work out what is at risk in your home and where to look.

What they are actually after

Larvae feed on keratin, the protein found in wool, hair, fur, feathers and silk. That explains why jumpers, blankets, coats with fur trims, tapestries and woollen carpets are targets.

Clean fabric is less attractive than soiled fabric. Perspiration, food spills and body oils make a garment easier to digest, so a jacket worn once and put away dirty is more vulnerable than one that has been laundered.

Fabrics that are usually safe, and one catch

Pure cotton, linen and most synthetics are not a food source for the larvae, and are much less likely to be damaged. The catch is blends. A fabric that is part wool is still worth protecting, and larvae will sometimes chew through synthetics to get at something they prefer.

They also feed on dust that has built up from shed hair, skin flakes, pet fur and lint, which means a heavily soiled synthetic carpet can still support a small population.

• At risk: wool, cashmere, mohair, silk, fur, felt, feathers
• At risk: pet hair and lint trapped in carpets and vents
• Lower risk: cotton, linen, polyester and nylon on their own
• Blends containing wool still count

How the damage develops

Adults lay eggs on suitable material, and the larvae hatch and feed for weeks or months depending on temperature and food. Warm, centrally heated homes can allow breeding for much of the year.

In carpets, grazing often starts at the edges and under furniture and spreads as a patchy, irregular thinning. In wardrobes, the first sign may be several small holes in one area of a garment, not one big hole.

The hiding places people forget

The usual suspects are wardrobes and chests of drawers, but larvae are just as happy under a sofa, beneath a bed, in the felt of a piano, inside a rolled-up rug or behind a radiator.

Look also at unused airing cupboards, boxes in the loft, old stuffed furnishings and wherever stored textiles have sat undisturbed for a long time. A dead bird, wasp nest or rodent nest in a void can also provide a food source that keeps a population alive.

• Underlay and the gap along fitted carpet edges
• Upholstered furniture, particularly under cushions and the base
• Stored rugs, throws and blankets in boxes or bags
• Piano felts, curtains and tapestries

Why identification matters

Carpet beetle larvae are often confused with moth larvae. They are small, hairy and also feed on natural fibres, but they need a different approach.

If you find larvae and are unsure what they are, keep one in a sealed pot or take a sharp photograph. Essex Pest Solutions can identify the cause during an inspection, which avoids spending time on the wrong treatment.

Frequently asked questions