Care & Repair
Moths are after the protein, which decides everything about storage
Clothes moth larvae eat keratin and nothing else, and once that is clear, most of the folk remedies sort themselves into the ones that work and the ones that do not.
What is eating the jumper
The adult clothes moth does not eat clothing. It has no functional feeding apparatus for it, and its entire adult role is to find a suitable site, mate and lay eggs. The damage is done by the larvae that hatch, and they eat for weeks or months before pupating.
What they eat is keratin, the structural protein in wool, cashmere, mohair, alpaca, feathers, fur and hair. They can digest it, which very few creatures can. They will not eat cotton, linen or synthetics — though they will chew through such materials to reach wool behind them, and they will feed on a blend for the wool content in it.
This single fact organises everything else. If the problem is an insect that needs protein fibre, then protecting protein fibre is the entire task, and cotton shirts in the same wardrobe are not at risk in themselves.
They prefer clothes you have worn
Larvae do better on wool carrying traces of perspiration, food and body oils than on scrupulously clean wool, which supplies additional nutrients and moisture that pure keratin does not. In practice, the garment that gets eaten is the one put away at the end of the season without washing.
They also want darkness and stillness. Eggs are laid in folds, in seams, in the underside of a collar, at the bottom of a drawer, in a garment bag that has not been opened since spring. A jumper worn every fortnight is disturbed too often to be a good nursery.
And they like undisturbed corners more than open rails. Carpet edges under furniture, the back of a deep wardrobe, a box in a loft — those are where an infestation establishes itself, and the clothing damage is often a symptom of a population living somewhere else nearby.
Cleaning first, then sealing
Everything follows from that. Wool goes into storage clean, without exception, because storing it dirty is providing food. Washing or dry cleaning also kills any eggs already present, which matters more than it sounds, since an infestation usually arrives inside a garment rather than through a window.
Then seal it. A genuinely airtight container or a sealed bag prevents new eggs being laid, and this does more than any repellent. Loose cotton garment bags keep dust off and are useless against moths, since a moth simply walks in. Vacuum bags work; so do rigid boxes with a proper gasket.
Cold kills them, though it needs to be properly cold and held for days rather than hours, and the usual advice is to freeze, thaw and freeze again, because eggs survive a single freeze better than larvae do. It is a practical option for a small item and impractical for a coat.
Cedar and lavender, honestly assessed
Cedar oil and lavender are repellents, not insecticides, at the concentrations found in a wardrobe. They may discourage a moth from laying in a particular spot when the scent is strong. They will not kill larvae already feeding, and their effectiveness falls away as the volatile oils evaporate — which is why cedar blocks stop working within a year or two unless the surface is sanded back to release fresh oil.
The traditional mothball is a different thing altogether: it works by sublimating into a vapour that is genuinely toxic to insects, which requires an enclosed space to build up a lethal concentration, and which is why the smell is so pervasive and so slow to leave fabric.
Pheromone traps are worth understanding correctly. They catch male moths and are excellent at telling you whether you have a problem and roughly where. They are monitoring tools rather than a control method, and treating a full trap as a solution rather than as a warning is the common mistake.
Dealing with an infestation
The reliable approach is unglamorous and thorough. Empty the affected wardrobe completely, clean or freeze every protein-fibre garment in it, and vacuum the space itself — corners, cracks, the underside of shelves and the carpet edge beneath — then dispose of the vacuum contents outside.
Check adjacent soft furnishings, because wool carpet, rugs and upholstery are frequently the reservoir feeding a wardrobe. If garments keep being damaged after the wardrobe has been cleared, the population is almost certainly living somewhere else in the room.
And accept that damage already done is done. Small holes in knitwear can be darned or invisibly mended by someone skilled, and on a good garment that is well worth the cost. What you are preventing from here is the next round.
Common questions
Are moth holes always from moths?
No, and misdiagnosis is common. Carpet beetle larvae eat the same keratin and cause similar damage, and they are at least as frequent in many homes. Beetle damage tends to be more scattered and the larvae leave shed skins behind. The control measures overlap almost entirely, so the practical response is the same.
Is it safe to store wool in plastic?
In a sealed container, yes, provided the garment is completely dry when it goes in, since trapped moisture encourages mould and mildew. Some people prefer breathable storage for long periods for that reason. A dry garment in a dry sealed box in a stable indoor temperature is fine for a season.
Do moths attack silk?
Silk is a protein fibre and is eaten, though generally less readily than wool, since it lacks some of what larvae thrive on. In practice silk garments in a wardrobe with a moth problem do get damaged. Treat them with the same caution you give wool.
Tara has written about fit, fabric, care & repair for most of the last decade and prefers a plain explanation to a clever one.