Clothes Moths: Why Putting Away Summer Clothes in September 2026 Triggers an Infestation

Late August is, in households across the Paris region, the moment of the great wardrobe changeover. Summer clothes get folded away, and out come the jumpers, coats and scarves that have sat at the back of a wardrobe for nine months. And it is at precisely that moment that a great many households discover round holes in a cashmere sweater, a coat sleeve worn thin in patches, or a carpet gone bald under a piece of furniture.

The reflex is almost always the same: blame the little beige moth that flutters out when you open the wardrobe door. That is a diagnostic error, and it explains why so many treatments fail. The adult moth has no functional mouthparts: it eats nothing at all. The damage is exclusively the work of its larvae — invisible, and busy for months in the darkness. Understanding this time lag is the key to understanding why a different approach is needed.

Technician in a protective suit spraying a treatment around a bed in a bedroom

What a clothes moth really is

The generic term "moth" actually covers two distinct species of small lepidoptera, not to be confused with the pantry moths that colonise kitchen cupboards.

The vast majority of household infestations in France involve Tineola bisselliella. It is a remarkably discreet insect: the adult avoids light, never comes near lamps in the evening (unlike ordinary night-flying moths) and flies in short, jerky hops just above the shelves.

A very particular diet: keratin

The clothes moth larva digests keratin, the fibrous protein that makes up wool, silk, cashmere, angora, mohair, fur, feathers, leather and even animal hair. It is a rare biochemical ability: very few organisms can break the disulphide bridges in this protein.

The decisive practical consequence: a garment made of 100% cotton, linen, polyester or viscose is not attacked — unless it is stained with sweat, sebum, milk or food. Those organic residues supply the extra nitrogen the larva cannot find in plant fibre, and a cotton T-shirt put away dirty can then end up perforated.

This is the point most people miss: moths do not attack at random. They go first for:

• Areas that have been worn and not washed: collars, armpits, cuffs, linings
• Garments put away straight after use, without a wash or a trip to the dry cleaner
• Wool–synthetic blends, as long as there is keratin left to consume
• Wool rugs under heavy furniture, carpet along the edge of skirting boards
• Piano felts, wall hangings, antique horsehair-stuffed seating

A cycle that explains the seasonal lag

The full cycle takes two to three months in a home heated to 22–25 °C, and can stretch to two years in a cold space. The female lays 40 to 100 eggs, glued to the fibre and barely 0.5 mm across. The larvae hatch in 4 to 10 days and feed for several weeks to several months depending on temperature, spinning small silk tubes mixed with fibres, before pupating.

In other words: the moth you see flying off in August is not the culprit behind the holes you discover the same day. It is the result of a larval population established since spring, or even since the previous winter. Seeing an adult means a complete cycle has just been finished off in your home.

Why infestations are on the rise in modern homes

For the past fifteen years or so, entomologists have observed a resurgence of clothes moth reports across Western Europe, after the phenomenon had declined sharply in the post-war decades. Several factors combine.

Continuous heating removes the winter pause

In an older, poorly heated home, moths went through a marked winter slowdown: a single generation per year. In a well-insulated Paris-region flat kept at 20–22 °C all year round, the cycles follow one another without interruption. That takes you to three, even four generations a year. Growth becomes exponential instead of linear.

The return of natural fibres

The vogue for natural materials, the popularity of cashmere and merino wool, and the rise of second-hand and vintage have massively reintroduced keratin into wardrobes. A garment picked up at a flea market or a charity shop is a classic vector of introduction: it may carry eggs invisible to the naked eye, stuck in a seam.

Low-temperature washing

Washing at 30 °C, environmentally virtuous as it is, kills neither eggs nor young larvae. You need at least 55 °C for 30 minutes, or a spell at sub-zero temperatures, to destroy every stage. And wool tolerates neither easily — hence the value of the methods set out below.

Cluttered, poorly ventilated homes

Moths hate light, draughts and movement. A wardrobe opened twice a year, an attic trunk, an under-bed space full of storage bags, a dressing room packed to bursting: these are perfect habitats. In the interventions we carry out across the Île-de-France region, the overwhelming majority of infested homes share the same profile — a textile storage area that is never disturbed.

Identifying an infestation: the five reliable signs

Before treating, you need confirmation. Here is what to look for, methodically, with a torch.

1. The holes themselves. Round or irregular, 1 to 5 mm across, often clustered, and generally located on fold lines or areas that touch the body. A perfectly clean, isolated hole on a seam is more likely mechanical wear.
2. Cases and silk threads. Tiny whitish tubes, 5 to 10 mm long, clinging to fabric or in the corners of drawers. This is the most specific sign.
3. Droppings. Sandy granules the colour of the fabric consumed — the larva excretes the dye. On a navy jumper, they are dark blue.
4. The larvae. Translucent creamy white, brown head, 8 to 12 mm at most, soft-bodied. Not to be confused with carpet beetle larvae (see below), which are hairy and reddish-brown.
5. The adults. Beige, running across shelves rather than flying. Their presence in a room with no textiles suggests a source in a duct, a crawl space or a bird's nest in the roof.

Beware the false diagnosis: roughly a third of the "moth attacks" we come across are in fact the work of varied carpet beetles (Anthrenus verbasci), small round beetles whose hairy larva also feeds on keratin. The treatment is similar, but the source differs: adult carpet beetles feed on pollen outdoors and come in through windows in spring, often from window boxes or a bird's nest under a cornice.

The five-step eradication protocol

No insecticide spray will resolve a moth infestation on its own. Treatment rests on a logical sequence in which each step sets up the next.

1. Empty the area completely

This is non-negotiable. A wardrobe treated by halves is reinfested within one cycle. You take everything out: clothes, garment bags, shoes, boxes, blankets — and inspect item by item in daylight. Take advantage of the clear-out to sort: clothes you haven't worn in three years feed moths without benefiting anyone.

2. Treat every textile with heat or cold

Eggs are the hardest target; they resist contact insecticides and repellents.

• Wash at 60 °C: ideal for cotton, linen, sheets and covers. Effective against all stages.
• Tumble dryer, 30 minutes on high heat: highly effective, including for items washed cold.
• Freezing at −18 °C for a minimum of 72 hours, in a hermetically sealed plastic bag: this is the solution for cashmere, silk and delicate wools. Take the bag out afterwards and let it return to room temperature before opening, to avoid condensation on the fibre.
• Professional dry cleaning: destroys all stages; reserve it for structured pieces (coats, suits).
• Dry steam: a high-temperature steam cleaner lets you treat armchairs, rugs, curtains and the insides of cupboards, where washing and freezing are impossible. Move slowly, nozzle in contact with the surface, concentrating on seams and folds.

3. Vacuum and sanitise the container

An empty wardrobe is worked from top to bottom: ceiling, sides, back, grooves, drawer runners, dowel holes, and the skirting board or floor underneath, where dust and hair accumulate. A vacuum cleaner with a narrow nozzle is more useful here than any product. Throw the bag away immediately, outside, in a closed bin.

A wash with hot water and white vinegar, followed by thorough drying before everything goes back in, completes the operation. Older pieces of bare, heavily cracked wooden furniture deserve a pass of steam along the joints.

4. Trap to measure, not to treat

Pheromone moth traps — sticky tablets releasing the female sex attractant — capture adult males. They are never enough on their own to eradicate a population, but they are irreplaceable as a diagnostic tool: placed in each room, they pinpoint the real source (that is where they fill up fastest) and measure the decline after treatment. Count and record the catches each week; if the curve doesn't fall after six weeks, a source has been overlooked.

5. Put the textiles back properly

Nothing goes away dirty. Nothing goes away damp. Animal-fibre items that won't be worn for several months should be stored in vacuum storage bags, or in rigid boxes with a gasket. The principle is mechanical: a moth cannot pierce an intact plastic film, and a female shut out cannot lay eggs inside.

What really works as prevention — and what doesn't

Natural repellents: useful, but widely misunderstood

Lavender, red cedar, bay leaves, cloves and patchouli have a documented repellent effect on females looking for a laying site. But two major limits apply:

• They kill neither the eggs nor the larvae already established. Putting sachets in an infested wardrobe achieves nothing.
• Their effectiveness drops off very quickly: essential oils evaporate within a few weeks. Red cedar wood blocks need sanding with sandpaper every two to three months to reopen the pores and release thujaplicin again.

Used as a complement in a wardrobe that has been cleaned out, they make sense. Used as a treatment, they simply sustain an illusion.

Mothballs: forget them for good

Naphthalene and paradichlorobenzene mothballs, long the standard, are banned from sale to the general public in the European Union because of their toxicity and their classification as suspected carcinogens. ANSES regularly points out, in its alerts on domestic biocides, that banned products continue to circulate via online platforms or informal imports. Don't bring this kind of product back from abroad: the health risk in an enclosed home, and particularly for children, is real and out of all proportion to the damage to your clothes.

The habits that make a difference all year round

• Air out and open wardrobes regularly: light and movement discourage egg-laying.
• Never put a worn woollen garment away without brushing it thoroughly. A boar bristle clothes brush removes organic residues and surface eggs from a coat that can't be washed every week.
• Vacuum under beds, behind chests of drawers and beneath wool rugs at least once a month. These are the number one source areas.
• Systematically inspect any second-hand purchase before it goes into the wardrobe: seams, hems, lining. If in doubt, 72 hours in the freezer.
• Check that there is no accessible bird or rodent nest in the loft: feathers and hair are natural reservoirs of clothes moths that reseed the home every year.

When to call in a professional

Home treatment is enough in most cases. Calling in a specialist firm becomes relevant in four situations:

1. Multi-room infestation: moths present in several rooms with no storage connection between them, suggesting a hidden source (loft, floorboards, ducting, wool insulation).
2. Heritage textiles: Oriental rugs, tapestries, stage costumes, collections. The combination of controlled anoxia and professional cold treatment avoids damaging the piece.
3. Premises open to the public: hotels, ready-to-wear boutiques, theatres, museums, where the economic and reputational damage justifies instrumented monitoring by trapping.
4. Recurrence after two full treatments, a sign that a source has not been identified.

A professional starts by providing a diagnosis — distinguishing clothes moths from carpet beetles, locating the source — before any treatment. In the Île-de-France region, where old buildings, shared lofts and communal cellars multiply the reservoirs, this inspection phase often represents the bulk of the intervention's value.

The key takeaways

The clothes moth is not a spectacular scourge like the bed bug or the rat: it doesn't bite, transmits no disease and poses no direct health risk. It simply costs a great deal, silently, by destroying the most durable things in a wardrobe.

Its weakness is its way of life: it needs darkness, stillness and dirty animal fibres. Three perfectly controllable conditions. A full annual clear-out of the wardrobe at the change of season, systematic washing before long-term storage, a few airtight bags for precious items and two or three monitoring traps are enough, in the vast majority of cases, to never again find a hole in a cashmere sweater one September morning.