Finding a hole in a favorite wool jumper is frustrating, but the cause is not always moths. Friction and washing can damage wool too, and the fix depends on the cause. This guide helps you work out what happened, deal with any infestation, repair the hole and avoid a repeat.
What causes holes in wool
Three causes account for most holes in woolen clothes.
- Clothes moth larvae. The larvae of clothes moths feed on keratin, the protein in wool and other animal fibres such as cashmere and silk (see cashmere vs cotton). The adult moths do not eat fabric, but the larvae do.
- Friction wear. Rubbing against belt buckles, seatbelts, bag straps, desks or zips can wear thin spots that eventually break.
- Washing and chemical damage. Harsh detergents, bleach or rough handling can weaken wool over time. Detergents containing enzymes aimed at proteins may not suit protein-based fibres, so a wool-specific product is usually the safer choice.
Pests such as carpet beetle larvae can also damage wool and other natural fibres.
Moth holes vs friction holes
The pattern of damage gives useful clues, though it is not always definitive.
- Moth damage tends to be small, scattered holes in random places, sometimes with thin patches or bare spots where fibres have been eaten from the surface. You may also see silky webbing, cases or tiny larvae in folds, seams and hidden areas. Garments that were stored unwashed or in dark, undisturbed places are at higher risk.
- Friction damage tends to appear where the garment rubs, for example on the hem, cuffs, elbows, waist or under the arms. The fabric looks worn and thin before breaking, rather than having random holes.
If you are unsure, look inside the garment and check along seams and folds for webbing or larval cases.
What do wool-eating moths look like?
The common clothes moth is small, usually golden or buff in color, and has narrow wings with a fringe. It tends to avoid bright light and is often seen fluttering weakly or running over surfaces rather than flying strongly toward lamps. The damaging stage is the larva, a small, creamy-white caterpillar that may be hard to see in fabric folds. Other pantry moths are sometimes mistaken for clothes moths, so look for activity around your clothes before assuming.
What to do if you find moth holes
- Isolate the item. Put it in a sealed bag so any larvae or eggs do not spread to other clothes.
- Inspect nearby items. Check other wool, cashmere, fur, silk and stored items in the same drawer or wardrobe.
- Treat the garment according to its label. Washing or dry cleaning can remove larvae and eggs, but wool can shrink or felt in hot water, so follow the label rather than raising the temperature. Freezing is a gentler option for many items: sealing the garment in a bag and keeping it in a freezer for a number of days is a commonly recommended method, though advice on timing varies.
- Clean the storage area. Vacuum drawers, shelves, wardrobe corners and floor edges, including along skirting boards, then wipe down surfaces.
- Wash or dry clean other at-risk items before returning them to storage.
- Monitor. Pheromone traps can help show whether moths are still active, but they do not replace cleaning.
For a heavy or recurring infestation, or for valuable garments, a professional pest controller or specialist dry cleaner can advise.
How to fix a hole in a woolen jumper
Repair works best when the hole is small and treated early, before it spreads.
- Darning. Using a needle and a yarn that matches the garment, weave stitches across the hole in one direction, then the other, to rebuild a woven patch. Darning mushrooms or eggs can help hold the knitted fabric steady.
- Needle felting or wool-fixing kits. Small holes and thin spots can sometimes be repaired by felting loose wool fibres into the fabric with a barbed needle. The result depends on the wool and the size of the hole.
- Patching. For elbows or larger holes, a patch on the inside or an applied decorative patch can strengthen the area.
- Invisible mending. A specialist can often reweave a damaged area so it is hard to see. This can be worth considering for expensive pieces.
- Stop the spread. For a very small hole, a few stitches around the edge can stop the knit from unravelling until you have time to mend it properly.
Before you start, wash the garment according to its label so you do not trap any larvae or eggs under the repair.
Preventing holes in wool
- Clean before storing. Moths are attracted to body oils, sweat and food traces, so wash or dry clean wool before putting it away for the season.
- Store in sealed containers or garment bags that close completely.
- Air and rotate clothes. Moths prefer dark, undisturbed places, so use and brush your wool regularly.
- Use cedar or lavender as a supplement. These may help deter moths, but they are not a reliable solution on their own and are not a substitute for cleaning.
- Protect from friction. Be aware of belts, bag straps and seatbelts rubbing the same spots.
- Wash gently. Use a wool-friendly detergent and a gentle cool cycle or hand wash, following the label.
If you also want to press woolen items, our guide to ironing by fabric type covers using steam and a pressing cloth safely. For pilling on wool knits, which is a separate problem from holes, see fabrics that don’t pill.
When to get help
If a garment is sentimental or expensive, or the damage is extensive, ask a tailor or specialist mender before attempting repairs yourself. If you see repeated signs of moths despite cleaning, a pest professional can help identify the source.
Frequently asked questions
What causes holes in a wool sweater?
Most often clothes moth larvae, friction against belts, bags or surfaces, or damage from harsh washing. Looking at where the holes are, and what the edges look like, helps identify the cause.
Can you fix a hole in a woolen jumper yourself?
Often yes, for small holes. Darning with matching yarn, needle felting or patching can all work. Larger or very visible holes may be better handled by a professional mender.
Do moths eat synthetic fabrics?
Clothes moth larvae feed mainly on animal fibres, but they may damage blends and can also feed on soiled synthetic items. Clean items in storage are the best defense. For how synthetics compare with natural fibres, see nylon vs cotton.
Is wool or cotton better if I want to avoid moth damage?
Moths generally ignore plant fibres such as cotton, which is one factor in the wool or cotton decision. The same trade-off comes up for tailoring in wool vs cotton suits.