Wool, Silk, and What They Will Not Eat

At risk

Anything That Came Off an Animal

Keratin is the structural protein in animal hair, wool, fur, feathers, horn and skin. The larvae have the unusual ability to digest it, which is why they can live somewhere as unpromising as a carpet.

• Wool - carpet, rugs, knitwear, suiting, blankets, felt
• Cashmere, alpaca, mohair, angora
• Silk - and silk highlights in an otherwise woollen rug
• Fur, sheepskin and shearling
• Feathers and down - pillows, duvets, jackets
• Horsehair, used as filling in older upholstery
• Taxidermy, and animal-hair brushes
• Wool-rich underlay, including old felt underlay

Not at risk

Plant Fibres and Synthetics

Cotton, linen, jute, sisal, bamboo, viscose, polyester, nylon, acrylic and polypropylene contain no keratin and are not food. A polypropylene carpet is simply not going to be eaten.

This is more useful than it sounds, because it lets you narrow down a house quickly. If the fitted carpet is synthetic, the damage you have found is in something else - the rug on top, the underlay beneath, or the wardrobe upstairs - and looking for it in the carpet is a waste of an afternoon.

Blends are the fiddly case. An 80/20 wool-polypropylene carpet, the commonest specification in British houses, is eaten perfectly happily; there is plenty of wool in it. Check the label or the offcut in the loft rather than guessing from how it feels.

The exception

Dirty Synthetics

Larvae will graze a synthetic textile that is soiled - with food, sweat, body oils, urine or hair - because what is on it is edible even though the fibre is not. The damage is usually shallower and more localised, and it is concentrated exactly on the soiled area.

It also explains the wardrobe pattern more generally. A wool jumper worn once and put away unwashed is far more attractive than a clean one, and it is one of the few pieces of prevention advice that genuinely works: clean before storing.

What this means

Two Practical Consequences

When you are choosing a floor covering, and you have had moths, synthetic removes the problem for that floor entirely. Whether that is the right choice for a period house is a different question, and plenty of people rightly decide it is not.

When you are deciding what to worry about, sort the room by material before panicking. In most houses the actual at-risk list is shorter than people expect: the rug, the stair runner, three jumpers and a coat.

Short answers

Carpet Moth Questions

Going further

Carpet Moth Guides