Clothes Moths: Why October Is the Month They Ruin the Woollens You've Just Unpacked

The typical call comes in during the first two weeks of October, often on a Sunday evening. The homeowner has pulled the boxes down from the top of the wardrobe, unfolded the merino jumper put away back in May, and found three clean holes at the shoulder. Then a fourth on a coat. Then a wool rug in the living room with a worn patch under the sofa, exactly where nobody ever vacuums.

The reaction is almost always the same: "it must have happened this summer, while we were away." That's right about the timing and wrong about the cause. The damage was done by larvae quietly feeding for four months in the dark. The adult you squash against the wall in October eats nothing at all — it doesn't even have functional mouthparts.

That's the whole misunderstanding at the heart of clothes moth control. People go after the fluttering moth, when the real problem is a population of larvae settled into the fibres, into the skirting boards and under the furniture.

The adult clothes moth does not feed and lives two to three weeks; its only role is to lay 40 to 100 eggs on a keratin-rich substrate. Killing the adults you can see therefore does almost nothing to reduce future damage: you have to reach the eggs and larvae, which account for more than 95% of the actual population.

This article sets out how to identify the species involved, why October is the month the damage is revealed, and which protocol to follow — treatment then storage — so you don't relive the same scene next year.

Brown, damp-furred rodent resembling a rat, perched on a stone at the edge of dark water

Identification: clothes moth, pantry moth or something else?

Many treatments fail because the species was misidentified. Three small brown insects fly around French homes, and they are not treated in the same place.

Three decisive field clues:

• Behaviour around light. The clothes moth avoids lighting and scurries more than it flies. A moth circling the kitchen pendant light is a pantry moth, and the problem is in a food cupboard, not the wardrobe.
• The presence of cases and droppings. Tineola larvae leave translucent silken cases stuck to the fabric and tiny granules the colour of the fibre they've eaten. An infested blue jumper produces blue droppings: that's a conclusive indicator.
• Where the holes are. Moths attack dark, undisturbed, soiled areas: collars, underarms, lapels, the underside of rugs, inner folds. An isolated hole in the middle of a jumper worn every week is more often mechanical wear or a burn.

Why clean wool is less often attacked

The larva digests keratin, but it also needs nitrogen and salts. Residues of sweat, sebum, saliva or food stains on an animal fibre sharply increase larval survival. That's why a woollen garment stored without washing at the end of the season is always more affected than a jumper that was washed before storage: technical notes from applied entomology laboratories and museum conservation guidance (notably that issued by the Centre de recherche et de restauration des musées de France on integrated pest management for collections) all stress this point.

Why October is when the discoveries pile up

The biological calendar explains the seasonality, and it's worth laying out clearly.

Two aggravating factors have become more significant in recent years in the Paris region:

1. Hotter summers and poorly ventilated homes. A cupboard against a south-facing wall can stay above 26 °C for weeks. That gains a whole extra generation over the season.
2. The return of natural fibres. The replacement of acrylic with wool, linen and cashmere in wardrobes — a long-term trend — puts exactly the substrate Tineola bisselliella needs back on the market. Pure synthetic fibres are indigestible for it; it only chews through them if a blend contains wool.

Brown and white rat in a wire cage, sitting on a wooden platform

The assessment to carry out before treating anything

A treatment launched without mapping the problem always leaves a focus of infestation behind. Allow one to two hours, done in a single session.

1. Empty the suspect unit completely

Not partially: completely. Every animal-fibre item is inspected in daylight or with a head torch, inside out, unfolding collars and hems. Moth holes are irregular, with clean edges, often clustered — unlike cigarette holes (singed edges) or wear (stretched fibres).

2. Look for non-textile sources

This is the step householders skip, and it explains most recurrences. The larva also develops on:

• dust rich in hair and skin flakes built up beneath skirting boards and behind low furniture;
• the underside of wool rugs and their fringes, particularly under sofas and beds;
• the felt on chair pads, upright pianos, drinks coasters;
• insect carcasses and birds' nests in roof spaces — a useful reminder: an abandoned pigeon nest on a balcony is a classic reservoir;
• forgotten old textiles: a felt suitcase cover, hats, fancy dress costumes, a box of knitting wool.

3. Gauge the pressure with traps

To know whether the infestation is residual or active, nothing beats counting. Pheromone traps for moths — sticky boards that attract male Tineola — placed one per affected room and checked weekly give you a readable curve: two catches a week and falling means the episode is ending; eight catches a week and rising means there's an active source you haven't found. These traps don't treat anything — they inform. That is their only genuine value.

Treatment: what really works on eggs and larvae

Cold and heat, the two most reliable weapons

Moth eggs stand up well to contact insecticides and badly to extreme temperatures.

Freezing is the cheapest option for a wardrobe of fine fibres: it doesn't distort anything and needs nothing more than a freezer and some bags. For bulk, vacuum storage bags gain you a factor of three or four on available space and then double as airtight storage. The critical point, often missed: the temperature must come back up gradually and the bag stays sealed until the textile has returned to room temperature, otherwise condensation will mark the fibres.

Vacuuming, a non-negotiable step

A vacuum cleaner with a HEPA filter, passed slowly over skirting boards, floorboard grooves, the backs of cupboards, and both the underside and the reverse of rugs, removes eggs, larvae, cases and keratin-laden dust — in other words both the population and its larder. The bag is then sealed and taken out of the home immediately. In an infested wardrobe, two passes a week apart beat a single very thorough one.

Insecticides: useful, but with limits

Contact products based on pyrethroids (permethrin, deltamethrin) work on adults and exposed larvae, not on eggs protected within the fibres. Two rules we repeat every time:

• Never spray directly onto a garment worn next to the skin. You treat the structures: the base and sides of the emptied unit, skirting boards, grooves.
• Follow the label. ANSES regularly points out that household biocidal products are overused and applied in poorly ventilated homes; the Direction générale de la santé and ANSES recommend airing rooms for at least thirty minutes after application and keeping children, pregnant women and animals out of treated rooms. Investigations by 60 Millions de Consommateurs into domestic pest-control products have shown that most users exceed the stated doses.

What doesn't work, or barely does

• Mothballs (naphthalene): banned from sale to consumers in the European Union since 2008 because of their toxicity. If you find some among inherited belongings, they go to the recycling centre, not into a cupboard.
• Lavender and cedar on their own: they have a partial repellent effect on females looking for a place to lay, and none at all on larvae already established. Red cedar wood blocks still have a preventive role, provided you sand them back with glasspaper twice a year — the volatile oil is exhausted within a few months.
• "Shock" aerosol sprays in a closed room: they kill the visible adults and create the illusion of a result, without touching the source.

Storing for next year: the end-of-season protocol

This is where it's all decided. A wardrobe properly put away in May doesn't generate a phone call in October.

1. Nothing goes into storage without being clean. Washed or dry-cleaned, every time, even items that were "only worn twice".
2. Airtight storage, not simply covered. Garment bags with a full-length zip, in breathable non-woven fabric, block females from getting in; a split polyethylene dry-cleaner's cover blocks nothing and traps moisture. Plastic boxes with a seal are a good option for folded jumpers.
3. Get rid of the cardboard boxes. Corrugated cardboard is both a shelter and an egg-laying surface. Transfer everything into smooth, sealed containers.
4. Favour cool, dry spaces. A hallway cupboard is better than a trunk in an uninsulated loft or a damp cellar.
5. Air things out and handle them. Clothes shaken out, moved and exposed to light twice over the summer become a poor development site. It costs nothing and is one of the most effective measures there is.
6. Keep passive monitoring in place. One or two pheromone traps left in the wardrobe and replaced each quarter will flag a recurrence before it reaches the textiles.
7. Treat the rugs at the same time. Wool rugs rolled up and stored for the summer are the number one cause of infestations that "come back for no reason". Vacuum both sides, roll pile-side inwards, and wrap.

For valuable items — cashmere, suits, antique textiles — storage in a cedar chest remains the most durable conservation solution, because it combines relative airtightness, humidity regulation and a repellent effect. It isn't a treatment, but it's a container that never becomes a source of infestation.

When to call in a professional

Outside help is justified in four specific situations:

• Damage to valuable rugs or tapestries, where amateur treatment risks doing more harm than the insect.
• Diffuse infestation across several rooms with trap catches that fail to fall after six to eight weeks of a rigorous protocol.
• A suspected inaccessible source: loft, crawl space, partition wall, bird nest under the roof.
• Commercial premises: woollen clothing shops, upholsterers, second-hand dress agencies, hotels with carpets and heavy curtains, where regulatory and commercial pressure leaves no room for guesswork.

Professional intervention then brings two things a householder doesn't have: access to insect growth regulators (IGRs) that halt larval development, and a methodical inspection of non-textile areas that pinpoints the real source.

Remember just one thing: where moths are concerned, October creates nothing — it reveals. The appointment that matters is in spring, when you put things away. A woollen garment that is washed, placed in a sealed container and taken out twice over the summer will not be attacked — regardless of any product.

If you've found holes this week, start with the most thankless step: empty the unit, look for droppings the colour of the fibre, and check under the rug. In eight cases out of ten, the source is right there, and it has nothing to do with the moth you squashed against the ceiling.