How do I stop moths eating my wool and cashmere?

You do not have to give up nice knitwear. The moths you see flying do not eat anything. It is their larvae that chew holes, and they are fussy: they want natural animal fibres, ideally with a bit of sweat or food on them, somewhere dark where nobody disturbs them. Take away those conditions and your wool is far safer.

What larvae look for

• Animal fibres: wool, cashmere, mohair, alpaca, silk, felt, fur and feathers.
• Dirt on the fabric: sweat, skin flakes, food and drink marks. Worn-and-put-back items are at the most risk.
• Dark and still: the back of the wardrobe, the bottom of a drawer, under a bed, a rug edge under a sofa.

Keeping clothes safe

1. Clean before you store. Wash by the care label or dry clean anything going away for more than a few weeks, even if it looks clean.
2. Seal what you are not wearing. Zip bags, sealed boxes, or garment bags that close fully. Moths get through any gap, so a cover that is open at the bottom does not protect much.
3. Wear and move things often. Larvae dislike being disturbed and dislike light. Take pieces off the rail, shake and brush them in daylight now and then, especially folds, cuffs and collars.
4. Keep the rail and the floor under it clean. Vacuum under and behind it regularly. Fluff and hair collecting there can feed larvae.
5. Check new and second-hand wool before it joins the rest. If in doubt, seal it in a bag and freeze it for a week or so, then let it warm up in the bag.

An open rail is the hardest place to protect, because nothing is sealed. Keep the pieces you wear often there, and bag the rest.

Wooden floors and synthetic fibres

Two beliefs that let people down. Wooden floors do not keep moths away: larvae live in the clothes, in rugs, and in the gaps between floorboards where fluff and hair collect. A home with no carpet can still have clothes moths in the wardrobe.

Synthetic fibres are not eaten on their own, but they do not protect the wool hanging next to them, and blends with some wool in them can still be damaged. Holes in pure cotton or viscose are more likely from something else, such as wear, or carpet beetle larvae.

Carpets and rugs

Wool carpets are usually damaged where nobody walks: under beds, sofas and wardrobes, behind doors, along the skirting. Lift the edge of rugs and look for bare patches, silky webbing or small larvae. Vacuum those spots regularly, and move furniture now and then so nothing sits undisturbed for months.

Steam cleaning: heat kills the eggs and larvae it reaches. But heat and moisture can also shrink, felt or distort wool, fade some dyes and loosen backing. Before you buy or hire a steamer:

1. Check the carpet maker’s care advice if you have it.
2. Test a hidden patch first, such as inside a cupboard, and let it dry fully before you judge it.
3. Consider a professional carpet cleaner who works with wool, and ask whether they offer a moth treatment as well.

Do not replace a carpet until you have found and treated the source. New wool carpet laid over a moth problem is just more food.

Kids and pets: if you use any moth spray on carpets or fabrics, follow the label on where it can go and how long to keep children and pets off it. Keep pheromone traps out of reach, because the glue sticks to fingers and fur.

Check that it is working

A clothes moth pheromone trap near the rail and one in the bedroom will tell you whether males are still flying. Date them, count weekly, and expect catches to fall as the plan takes hold. See what pheromone traps can and cannot do. If you already have damage and moths in several rooms, start with clearing clothes moths without mothballs.