Carpet Moth Control

Start here

The Adult Does Not Eat

This is the single most useful thing on the page, so it goes first. A carpet moth does its eating as a larva — a cream grub a few millimetres long, living down in the pile where it is dark. The adult moth that eventually flies out of the floor has a different job entirely: it mates, it lays, and in some species it does not feed at all before it dies a fortnight later.

Almost everything people do about moths goes wrong here. A fly spray, a swatted moth at the window, a can of something emptied into the air — all of it is aimed at the one stage that is doing no harm. Meanwhile the damage carries on quietly under a piece of furniture nobody has moved since it was delivered.

It also explains the timing that catches people out. You see the moths in spring or on a warm evening, decide you have caught it early, and find the bald patch in October. The moths were the end of a cycle, not the beginning of one.

1. 1Egg. Laid straight onto the wool, in the dark - carpet edges, under furniture, inside a wardrobe. One female lays forty or fifty. They are about half a millimetre and you will not see them.
2. 2Larva — THE ONE THAT EATS. A cream grub a few millimetres long, often dragging a silk case it has camouflaged with fibres from your own carpet, so it looks like a grain of rice the same colour as the floor. This stage lasts weeks in a warm house and can last the best part of a year in a cold one. Every bit of the damage happens here.
3. 3Pupa. It spins up in a crevice - under the gripper rod, in a seam, in the pile at the edge of the room. Nothing is eaten at this stage and nothing much reaches it.
4. 4Adult. What you see. It does not eat cloth, and in some species it does not eat at all: it lives two to four weeks, mates, lays, and dies. Killing the adults you can see stops nothing that is already in the floor.

Identification

Which Moth Have You Actually Got?

Before anything else: most of the moths people bring us are not carpet moths. The big brown one bumping at the lampshade on a July evening came in through the window and will do nothing to your house.

A clothes or carpet moth is small. The body is six to eight millimetres, the wings nine to sixteen across — roughly a grain of rice with wings. It is buff, straw or speckled, the wings are narrow with a fringe along the trailing edge, and the giveaway is the behaviour: disturbed, it tends to run and drop into the pile rather than fly up at the light.

The other thing worth learning to see is the larval case. The case-bearing sort builds itself a little silk tube and camouflages it with fibres pulled out of your own carpet, so it ends up exactly the colour of your floor and looks like a grain of rice lying in the pile. People hoover past them for months.

If you are not sure, photograph it or keep it in a pot. It changes the treatment and it is free to ask.

What they eat

Wool, and Not Much Else

The larvae are after keratin — the protein in wool, silk, fur, feathers, cashmere and animal hair. That is why the damage lands where it does:

• wool carpet and wool-rich underlay
• rugs, and the wool side of a jute-backed rug
• knitwear, suits, coats and blankets in a wardrobe
• upholstery with a wool covering, and horsehair filling in older furniture
• felt, sheepskin, taxidermy, feather pillows and down

Cotton, linen, polyester, nylon, acrylic and viscose are not food. A polypropylene carpet is not going to be eaten. But a mixed room is the normal case — a synthetic carpet with a wool rug on top, or a wardrobe where two jumpers out of thirty are the wool ones — and a synthetic item that is heavily soiled can be chewed for what is on it rather than what it is.

That is genuinely useful when you are deciding what to worry about, and it is also why we ask what the floor is made of before quoting.

Where it happens

Dark, Undisturbed, and Next to Something Woollen

The larvae avoid light and they avoid traffic. So the damage is never in the middle of the room where you would notice it. It is:

• under the sofa, the bed, the wardrobe and the chest of drawers — particularly anything that has not moved in years
• along the edges of the room, in the pile against the skirting and over the gripper rod
• under a rug, on the side against the floor
• in the back corners of a fitted wardrobe, and inside stored bags and boxes
• behind long curtains, where the hem sits against the floor
• in a spare room, a loft or a holiday let that is shut up for months at a time

Which is why a survey means moving furniture rather than looking at a room. If nothing is lifted and nothing is pulled out, nobody has looked yet.

Treatment

What a Visit Actually Involves

The job has three parts and skipping any one of them is why treatments fail.

Finding the extent. Furniture comes out, rug edges come up, wardrobes get emptied enough to see the corners. We are looking for live larvae, cases, webbing, frass and the shape of the damage — which tells us whether this is one rug or a whole floor.

Reducing what is there. Thorough vacuuming, especially the edges, the gripper and under everything that moved, is not a token gesture. It physically removes eggs, larvae and cases, and it is the part you can help with most.

Treating where they live. A residual product goes into the edges, the pile and the places under furniture — not sprayed into the air, which achieves nothing. Affected garments and small textiles are usually better dealt with by heat or freezing than by anything chemical.

A follow-up visit is normal rather than a sign something went wrong. Eggs are the hardest stage to reach, so a second visit timed to catch what hatches afterwards is how the cycle gets broken. The products are safe when applied correctly and the technician will tell you what precautions apply during and after — say when you book if there are children, pets or anyone with a health condition in the property.

Photographs on this page are for illustration purposes only.

The honest bits

Four Things We Would Rather Say Now

Pheromone traps do not control anything. They catch male moths, and they are genuinely useful for telling you whether you still have a problem and roughly where. As a treatment they do nothing, and a trap filling up is information, not progress.

Some things cannot be saved. A carpet eaten through to the backing does not grow back, and a treatment stops the damage rather than repairing it. We would rather tell you the underlay and the carpet in one corner are finished than treat around it and let you find out at the same time as your flooring fitter.

Moth balls are not the answer, and the old ones are not legal. Naphthalene mothballs were withdrawn from sale in the UK and the Office for Product Safety and Standards still issues recalls when they turn up. Cedar and lavender are pleasant and they are not insecticides. There is more on this in the deterrents article.

If it came in with something, it will come back with the next thing. Second-hand rugs, auction furniture, stored textiles and inherited woollens are how most of these start. Treating the room without dealing with what brought them in buys you a year.

Where we work

Fifteen Towns

Commercial

Hotels, Offices, Lets and Anywhere With a Wool Floor

Commercial moth work is mostly about two things domestic work is not: access and records.

Wool carpet and wool-blend carpet tiles are common in offices, hotels, guest houses and older public buildings, and the quiet edges of a large floor plate — under fixed seating, behind filing, along the perimeter of a rarely used room — are exactly the conditions the larvae want. Attendance can be early, late or on a closed day so the premises keep trading.

The output is not only the treatment: what was found, where, what was applied, what was recommended and what is still outstanding. For a hotel dealing with a complaint, or a managing agent dealing with a tenant, that written record is what turns an argument into a scheduled job.

Going further

Carpet Moth Guides

Short answers

Carpet Moth Questions

One Last Thing

If you have a bald patch at the edge of a room and a couple of small moths a week, you have probably had this for longer than you think, and it is worth someone moving the furniture. If you have one big moth at the window, you almost certainly have nothing at all. Ring and describe it — there is no call-out fee for coming to look, and we would rather tell you it is nothing than turn up.