Bald patches under the sofa, tiny rice-grain-sized cases stuck to skirting boards, mottled little moths fluttering up when you draw the curtains — case-bearing carpet moths. They've quietly become a much more common Cornwall problem over the last decade, driven by milder winters and the increase in wool and natural-fibre flooring. This guide walks through identification, why DIY half-measures usually fail, and what professional treatment actually involves.
What you're actually dealing with
Two species commonly cause UK carpet moth damage:
- Case-bearing clothes moth (Tinea pellionella) — the most common Cornwall carpet pest in 2026. Adults 7-8mm, mottled pale silvery brown with three small darker spots on the forewing. Larvae carry a distinctive silk case (3-5mm, rice-grain shape, often coloured with fibres from the host material) as they feed.
- Common clothes moth (Tineola bisselliella) — slightly more uniform golden colour, no spots, larvae don't carry cases. More commonly attacks clothing than carpets.
The damage comes from the larvae, not the adults. Adult moths don't have functional mouthparts as adults — they don't eat. Their entire purpose is to mate, lay eggs, and die within a few weeks. The larvae do the damage, feeding on keratin — the protein in wool, silk, fur, feathers and hair.
This is why synthetic carpets (polypropylene, nylon, polyester) are largely safe; carpet moths can't digest synthetic fibres. Wool, wool-mix, silk, and natural-fibre rugs are the target, plus any natural-fibre soft furnishings, upholstery and clothing in the same room.
How to know it's carpet moths and not something else
The signs:
- Bald patches in carpets, particularly under heavy furniture, in dark corners, and along skirting boards where the carpet meets the wall
- Threadbare areas where the pile has been eaten away to the carpet backing
- Small silk cases (3-5mm) — rice-grain shape, sometimes incorporated with carpet fibres, stuck to skirtings, picture rails, the underside of furniture or the back of curtains. This is the diagnostic feature of case-bearing moths.
- Tiny adult moths (7-8mm, mottled pale brown) fluttering up when curtains are drawn, often in dark corners or near textile sources
- Larvae visible — tiny pale caterpillars (3-7mm) carrying their silk cases, found at the carpet/skirting junction or in dark cupboards
- Feel/sound — none; carpet moths are silent and slow-moving
What it's NOT: moths drawn to light at night are mostly other species — clothes moths and carpet moths are weakly attracted to light at best, and tend to scuttle in shadows rather than fly to lamps. If your kitchen has small moths around food (cereals, flour, dried fruit), those are pantry moths (Indian meal moth, Mediterranean flour moth) — a different problem requiring food-source removal rather than carpet treatment.
Why Cornwall is getting more carpet moth work
- Milder winters reduce overwintering die-off; larvae survive in skirting voids and under furniture year-round
- Wool carpets and natural-fibre rugs have become more popular in Cornwall holiday lets, period properties and conscious-consumer households — exactly the materials carpet moths target
- Holiday lets — properties unoccupied for weeks between guests provide quiet, undisturbed conditions for larvae to develop
- Granite and cob cottages have generous skirting voids and gap concealment perfect for moth pupation
- Second-hand rugs and vintage furniture often introduce eggs or larvae to a new property
- Less central-heating in Cornwall holiday lets out-of-season — cool damp conditions in some properties favour moth development
What professional treatment looks like (2026 Cornwall)
- Survey visit. Confirm species, identify scope (single room, multi-room, whole property), assess natural-fibre soft furnishings, identify sources (vintage rugs, wool-stuffed cushions, taxidermy, fur items).
- Preparation (your job). Vacuum thoroughly — including under furniture, along skirtings, behind beds and wardrobes. Wash any affected clothing or bedding at 60°C; freeze items that can't be washed (48 hours at ≤-18°C kills all life stages).
- Treatment application. Professional-grade residual insecticide — typically pyrethroid-based (cypermethrin, deltamethrin) or modern non-pyrethroid alternatives — applied to carpet surface, edges, skirting voids, under furniture, and any identified harbourages. Some controllers also apply Insect Growth Regulator (IGR) products that disrupt larval development.
- ULV fogging or smoke treatment may be added for severe cases or hard-to-reach voids
- Follow-up. Typically a second visit at 4-6 weeks to catch newly-hatched larvae from eggs that survived initial treatment.
- Pheromone monitoring traps. Often left in place to confirm clearance and as ongoing surveillance.
Indicative Cornwall pricing:
- Single-room treatment: £150-£250
- 2-3 room treatment (typical domestic): £250-£450
- Whole-property treatment (significant infestation): £400-£700
- Annual contract / monitoring for holiday lets: £180-£350
- Heat treatment of textiles (specialist): £200-£500
Why DIY usually disappoints
The over-the-counter approach:
- Buy a carpet moth killer aerosol or powder from a hardware shop
- Apply liberally to visible patches
- Notice a few less moths
- Six weeks later, fresh damage appears
- Repeat the cycle
The problems:
- Over-the-counter products are typically less effective than the professional residual products controllers use
- Eggs and larval cases are protected — the silk case provides some protection against contact sprays
- You can't reach the harbourages — skirting voids, under-floor edges, the underside of carpets at the gripper rod are all infestation hotspots that surface sprays don't penetrate
- Adjacent rooms are usually affected by the time you notice damage — partial treatment leaves a reservoir for re-infestation
- Pheromone traps catch only adult males — useful for monitoring, useless as a stand-alone treatment
- Vacuuming helps but isn't enough — a thorough vacuum removes eggs and surface larvae but doesn't reach pupae in skirting voids
DIY can be appropriate for very early-stage isolated activity (a single small patch caught fast). For anything established, professional treatment is the cheaper route once you factor in the cost of replacing damaged carpets.
Prevention — the long-term protection
Once you've cleared an infestation, prevention matters:
- Regular vacuuming — particularly under furniture, along skirtings, behind beds and wardrobes. Weekly minimum; twice weekly in heavily-furnished rooms.
- Move furniture occasionally — quarterly minimum; carpet moths thrive in undisturbed spots
- Cedar and lavender — moderate deterrent effect; pleasant smell; cheap. Use sachets in drawers, wardrobes, under sofas. Refresh every 3-6 months as the volatiles dissipate.
- Pheromone monitoring traps — provide early warning of returning adult males. Replace pheromone every 3 months.
- Wash or freeze second-hand items before introducing — vintage rugs, antique cushions, wool blankets, fur items, charity-shop clothing
- Manage humidity — well-ventilated rooms with normal heating discourage larval development. Damp, cold, undisturbed spaces favour them.
- Holiday lets: annual professional inspection and changeover-cleaner training to look for fresh damage and silk cases
What carpet moths cost in carpet replacement
If left untreated, carpet moth damage in a wool carpet can require:
- Patch replacement (matching wool, fitting, edge-bonding): £150-£400 per patch
- Whole-room re-carpeting (wool, supply + fit): £40-£120/m², typically £600-£3,000 per room
- Antique or specialist rug repair: £200-£2,000+ depending on rarity and damage
Compare to £250-£450 for 2-3 room professional treatment that prevents the damage in the first place. The maths almost always favours treating early.
Special cases — holiday lets and second-hand furniture
Two patterns we see repeatedly:
- Holiday lets with wool carpets: annual professional inspection (£100-£200) is the cheapest insurance against finding bald patches mid-season. Most Cornwall holiday-let aggregators (Sykes, Classic Cottages) increasingly note pest management as a standard.
- Vintage rugs and antiques: always inspect carefully before introducing to your home. Older Persian or Turkish rugs may carry overwintering larvae. A 48-hour freeze (≤-18°C) or a 60°C heat treatment before deployment kills any life stages.
Get a Cornwall carpet moth quote
Submit your postcode on the quote form and mention "carpet moths" in the notes. We match you with Cornwall pest controllers experienced with textile pests. See related: woodworm treatment, full Cornwall pricing, Falmouth, Truro, St Ives.