Clothes Getting Eaten By Moths? Here's What To Do

Winter is coming, and that means sweater season. But perhaps you’ve had a nasty surprise when you pulled them out of storage recently: tiny holes dotting your wool, silk, cashmere, or other natural fiber-based (and often expensive!) garments. The culprit? Moths.

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But fear not: these little blighters can be avoided – and it’s not even particularly difficult. Here’s the scoop.

Moths! In my closet?

If there’s anything in the house we expect moths to go for, it’s famously the lamp, right? And closets are usually dark – so why would there be moths there? 

Well, we’re talking about a couple of very specific types of moth. There are only really two common types of clothes moth: the webbing clothes moth, which is gold, and the case-bearing clothes moth, which is silver. Both are harmless, unless you’re a garment – in which case you’re liable to get chowed down on until you’re holey and ragged. 

Why? Because “the larvae of clothes moths are adapted to feed on keratin, a protein found in natural fibres,” explains the Natural History Museum, London (NHM). “Females lay eggs within natural fibres, which hatch between 4-10 days in summer months and up to three weeks in colder weather […] Larvae can cause serious damage to tapestries, carpets and clothing, leaving trails across woolen garments and removing hair from fur coats at the base.”

Unfortunately, that means that once you see actual moths, it’s too late. “Adults do not feed, obtaining all nutrients needed for their final life stage during larval growth, and cause no damage to fabrics,” notes the NHM, and their eggs – each moth can lay up to 100 each – are incredibly hard to see, being only about a millimeter in size.

And here’s the thing: once you have an infestation, it can be really, really difficult to get rid of them. “The only thing I’ve got left is either burn down my house or get the pest controllers in,” one homeowner told The Guardian back in 2019. “We’ve given up on repainting because all the walls are spattered. Every morning when I wake up there are about 10 or 12 on the wall […] Every time you’ve got rid of them, they appear again.”

Evidently, assuming you don’t want to be replacing all your knitwear and cocktail dresses each year, you’re going to want to deal with the problem before it gets out of hand. The good news? That’s totally possible, and, if you’re lucky, not too hard.

The bad news? It requires almost constant vigilance.

Clearing the problem

So, first things first: clean your clothes. “Dry cleaning is the most effective method of killing moth larvae, and it’s worth the expense for wool sweaters and jackets you don’t want to risk ruining,” advises the New York Times’s Wirecutter blog. While washing at home is an option, you’ll need to use hot water – at least 50°C/120°F, per the pros – and wool doesn’t tend to like those kinds of temps, so definitely check the labels before throwing them in the machine.

If the moths are in your carpets, by the way, these will need to be deep cleaned too. That can be done either by dry cleaning or steaming them.

Second, clean your closet. “Thoroughly vacuum your closet,” Wirecutter says. “Moths and larvae love dark corners and crevices. Remove the vacuum bag and discard it outside immediately, because it will probably be full of eggs and larvae.”

Once you’re sure they’re clean of moths and their offspring, there’s a very simple way to help guard against future infestations: bag them up. Vacuum packing them is a great option; plastic storage bins are also effective. Just make sure there’s no holes in the containers, and avoid fabric options – they’d basically just be a tasty appetizer before the moths’ main course.

Turning up the heat… and freezing them out

If you have items that can’t be dry cleaned or laundered, there are other options for ridding them of moth eggs and larvae. “A combination of sunlight and vigorously brushing the infested items” can kill them, advises Wirecutter. “But this can be dirty work; expect to get grimy, and take care not to track eggs or larvae back into your home.”

An easier option is to use extreme temperatures on your clothes: while washing your woolen items above 50°C isn’t usually a great idea, putting them in the oven at that heat for at least half an hour – some places recommend longer, just to be sure – can kill the moths at any stage of life. 

Of course, the problem here is that your clothes can scorch if left for too long at too high a temperature, and so you might prefer to go the opposite route: putting them in the freezer for days at a time – at least 72 hours once they reach freezing temperatures, Jason Dombroskie, manager at the Cornell University Insect Collection and coordinator of the Insect Diagnostic Lab, told Wirecutter.

It may sound wacky, but it’s scientifically sound. And there’s the weight of tradition behind this method, too: “When you look back at early housekeeping manuals, they say you should keep your fur coats and thick jerseys in the cold store over summer,” David Pinniger, an entomologist who works with museums and historical institutions, told The Guardian.

Smoke ‘em out

There’s a common idea that medieval folk used to keep their clothes in the toilets – it’s why their bathrooms were called “garderobes”, because they guarded the robes. The logic, we’re told, was simple: it was that the horrendous smell of pre-Renaissance effluence would keep away the moths.

Now, that’s most likely a myth. But the idea of using scents to deter moths isn’t completely without merit: herbal aromas like lavender are commonly recommended to repel the adult moths, as is the smell of cedarwood – that’s one reason why cedarwood chests are so popular for clothes storage.

However, there are some caveats here. The scents must be strong – and they will fade over time. Also, they’re not a sure thing – and “if the moth gets past your defences and lays eggs, [the smell] has no effect on the larvae,” Pinniger warned. 

That’s also true of smoke bombs and aerosol sprays, he advised: they’ll kill the moths, but not the eggs or larvae. To actually get rid of the wool-eating creepy crawlies, you’ll probably need to spray an actual insecticide – regular deep cleaning can “often […] be enough,” Nigel Blades, a preventive conservation adviser for the National Trust, told The Guardian, but “where we need to go beyond that, we use a commercial [insecticide] product […] to treat nooks and crannies where moths might like to hide away.”

Mothballs fall into this category too, by the way – and, while effective, they should probably be left as a last resort. They “are a pesticide, and breathing large amounts of the fumes can make you pretty sick,” warns Wirecutter. “Keep them out of reach of kids and pets (you don’t want either mistaking mothballs for candy), and sealed inside storage bins.” 

“If the health risks aren’t enough to dissuade you, consider that the chemicals in mothballs can soften plastic, which severely limits your storage options,” they add.

Tell ‘em to buzz off

If all else fails, maybe you can take a leaf out of various museums’ and heritage sites’ books, and wage full-on insectoid warfare against them.

Trichogramma pretiosum are a type of tiny wasp – “You can fit half a dozen on a pin head and still have room to spare,” entomologist and Bugs for Bugs founder Dan Papacek told ABC back in March – and “its sole mission in life is to seek out moth eggs and put their eggs in the eggs of the moth.”

“That egg hatches within the egg of the moth and consumes it from within,” Papacek explained. “Without moth eggs, they have no reason for being.”

As such, they’re fast becoming a cult hero anti-moth measure, with proponents raving about their effectiveness and “natural” credentials. And it’s true that it’s hard to see a downside: they’re so small as to be invisible; they’re harmless to just about anything that’s not a moth; they’re pesticide-free; and once they’re in your house, you can kind of just forget about them.

The result? A house that’s technically infested with wasps, yes – but also, hole-free knitwear. 

See: we told you wasps aren’t all that bad.

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