Carpet Moths: How to Spot, Treat & Prevent the Carpet Eater

Carpet moths are having a moment, and not in a good way. As wool carpet and rugs make a comeback and UK homes stay warmer for longer, the small buff-gold moth that quietly destroys wool has found ideal breeding conditions in thousands of living rooms. It's the larvae, not the fluttering adults, that do the damage — chewing through the protein keratin in wool, silk and cashmere while hidden under sofas, behind skirting boards and beneath furniture that hasn't moved in years.

By the time most people notice, there's already a bald patch where a bookcase used to stand, and eggs laid weeks earlier are still hatching elsewhere in the room. This guide covers how to tell carpet moth damage from ordinary wear, the treatment protocol that actually breaks the infestation cycle, what professional treatment costs, and the habits that keep moths from coming back once you've won.

Three trends have converged to help carpet moths spread. Wool carpet has become fashionable again after decades of cheap synthetic flooring — see our guide to how wool compares with nylon and polypropylene — and wool is exactly what the larvae need to survive. Central heating keeps homes warm right through winter rather than cooling down, so the breeding season barely pauses. And busy households increasingly rely on a quick vacuum pass down the middle of a room rather than getting into edges and under furniture, precisely where larvae prefer to feed undisturbed.

Soiled wool is also more attractive to larvae than clean wool — food spills, pet hair and skin flakes season the fibres in ways that seem to speed up feeding, which is one reason infestations often start near sofas or beneath pet beds rather than in an empty spare room.

Carpet moths are easy to miss until the damage is done, partly because the adults rarely fly far and the larvae actively avoid light. Look for:

• •Adults: small, roughly 7mm, buff-gold moths that scuttle across the floor or make short, low flights, rather than the fluttering circles of kitchen food moths.
• •Larvae signs: gritty, sand-like frass (droppings), tiny silken cases or webbing tubes woven into the pile, and tufts of carpet that lift away between your fingers.
• •Damage pattern: bald or thinned patches at room edges, under furniture, along skirting boards and beneath stair carpet — larvae avoid light and foot traffic, so busy, central areas are rarely affected first.
• •Where to check now: the undersides of rugs, carpet under sofas and beds, wardrobe floors, and any stored wool blankets or clothing.

A single vacuum and spray won't finish the job — carpet moth eggs hatch in waves over several weeks, so the protocol needs repeating to catch each new generation. Work through these steps in order:

• •1. Vacuum ruthlessly first, using the crevice tool along every edge, skirting board and both sides of any rugs, then empty the vacuum outside — you've just collected live eggs and larvae, and leaving them indoors reinfests the room.
• •2. Treat affected zones with a residual carpet moth spray, working it into edges, under furniture footprints and along skirting, following the label's ventilation times.
• •3. Wash infested textiles at 60°C where the fabric allows, or freeze them for 72 hours in sealed bags if not — both kill eggs and larvae without damaging most wool.
• •4. Repeat the vacuum-and-spot-treat routine every three to four days for a month. This is the step most people skip, and it's the one that breaks the egg cycle.
• •5. Recheck previously affected areas weekly for fresh frass or webbing for at least six weeks before declaring the room clear.

• •Vacuuming only the visible, walked-on areas and skipping edges, skirting and under furniture — exactly where larvae live and feed.
• •Emptying the vacuum bag or canister indoors, which simply relocates live eggs instead of killing them.
• •Treating once and stopping, rather than repeating over several weeks to catch eggs that hatch after the first spray.
• •Leaving stored wool jumpers, blankets or rugs folded away unwashed for months, giving larvae the undisturbed conditions they need to establish.

None of this needs specialist kit, but a few products make the difference between a treatment that works and one that just shifts the problem along the skirting board.

• •Vacuum with a crevice tool attachment: most vacuums already include one; a replacement tool costs around £5–£10.
• •Residual carpet moth spray: roughly £8–£15 per can, enough to treat a couple of average rooms.
• •Pheromone moth traps: packs of two to four for about £6–£12; they catch males only, so they work as an early-warning system rather than a cure.
• •Sealed freezer bags for textiles: a few pounds for a box large enough to fit jumpers or a small rug.
• •Professional treatment: typically £150–£400 for a full infestation visit including insecticide application and hot water extraction — see our UK pest control cost guide for a fuller breakdown.

Heavy or recurring infestations — multiple rooms affected, bald patches reappearing within weeks of treatment, or moths turning up in stored clothing as well as on the floor — are worth handing to a professional. A pest controller combines insecticide application with hot water extraction, which kills eggs, larvae and adults in a single pass at a depth a domestic vacuum can't reach, and deep-cleans the carpet at the same time. Because larvae prefer soiled wool, a properly cleaned carpet is also less appetising to any survivors — the same logic that makes removing ground-in stains and odours worthwhile even outside an infestation.

Prevention is mostly about refusing to give moths the dark, undisturbed conditions they need, and it costs little compared with even one professional treatment. This sits alongside general pest-proofing habits for the rest of your home — moths are just one of many pests that laxer housekeeping tends to let in.

• •Vacuum edges and under furniture monthly — this single habit prevents more infestations than any spray.
• •Shift furniture occasionally so no patch of carpet stays permanently shaded and undisturbed.
• •Store off-season wool clean and sealed rather than folded in an open drawer — see keeping wardrobes moth- and mould-free.
• •Keep pheromone traps in wardrobes and living rooms as an early-warning system, and restart the protocol if a trap catches more than the odd moth.
• •Get carpets professionally cleaned periodically — see how often carpets should be cleaned — alongside our wider tips on making carpet last longer.

**Do carpet moths bite humans or pets?** No — they feed only on keratin in wool, silk, feathers and fur. They're a nuisance to carpets and clothes rather than a health risk, though heavy infestations can trigger mild allergic reactions in sensitive people.

**How long does a carpet moth infestation take to clear?** Expect four to six weeks of repeated vacuuming and treatment to break the full egg-to-adult cycle, even after a professional visit, because eggs laid before treatment keep hatching for weeks afterwards.

**Can carpet moths live in synthetic carpet?** Not usually — nylon and polypropylene aren't a food source, so larvae rarely establish there, though they can still lay eggs in synthetic pile if it's wool-blended or wool-backed.

**Are carpet moths the same as clothes moths?** They're closely related species with near-identical habits, both attacking wool and other keratin fibres, so treating one usually means checking for the other in wardrobes as well as on the floor.

**Does mothballing help with carpet moths?** Mothballs work reasonably well on stored, sealed items but aren't practical across a whole carpeted room; a residual carpet spray plus consistent vacuuming is far more effective and less pungent.

**Will hot water extraction alone get rid of carpet moths?** The heat kills eggs and larvae on contact, but only where the machine actually reaches — corners and floor under fixed furniture usually still need separate spot treatment.