The short answer
Adult clothes moths live only a few weeks: about 37 days for males and 21 days for females at 18°C, according to MuseumPests. The larvae, which do the damage, can live from about 35 days to over two years. That long larval stage is why moth problems drag on.
The short answer
Adult clothes moths do not live long. MuseumPests, a conservation resource used by museums, says adult males of the common clothes moth live about 37 days and females about 21 days at 18°C. Adults do not feed, so they spend that time mating and laying eggs.
The larvae are a different story. They can live for a few weeks or for well over a year, depending on warmth and food. The figures below come from UC IPM (the University of California’s pest management programme), MuseumPests and English Heritage. They differ a little because conditions differ, so treat them as ranges rather than exact timings.
The four stages of the moth life cycle
1. Eggs
A female clothes moth lays around 40 to 50 eggs, spread over two to three weeks, according to UC IPM. Her larvae will need wool, silk, fur or feathers to eat, so the eggs tend to end up where those materials are.
Moth eggs are hard to spot. UC IPM says they hatch in 4 to 10 days in warm weather, and MuseumPests gives about 7 to 10 days at room temperature. In a cold room it can take longer.
2. Larvae
This is the only stage that eats, and the only stage that damages your things. Moth larvae are small, pale caterpillars that feed on keratin, the protein in animal fibres. The common clothes moth’s larvae spin silk webbing as they go. The case-bearing clothes moth’s larvae carry a silk case around with them.
How long the larval stage lasts depends a great deal on conditions. UC IPM gives a range of 35 days to 2.5 years, and MuseumPests gives 35 days to 2 years. Warmth and good food speed it up. Cold rooms and poor food slow it down, which is why a problem in a cool loft or spare room can quietly carry on for a long time.
3. Pupae
When a larva has finished feeding, it turns into a pupa. UC IPM says this takes about 8 to 10 days in summer and 3 to 4 weeks in winter.
4. Adults
The adult moth emerges, mates and lays eggs. Adults are weak fliers that avoid light, so you may only see them when you disturb a wardrobe or lift a rug. Then the cycle starts again.
The life cycle at a glance
| Stage | How long it lasts | Source |
|---|---|---|
| Eggs | 4 to 10 days in warm weather; about 7 to 10 days at room temperature | UC IPM; MuseumPests |
| Larvae | 35 days to 2.5 years | UC IPM (MuseumPests: up to 2 years) |
| Pupae | 8 to 10 days in summer; 3 to 4 weeks in winter | UC IPM |
| Adult males | About 37 days at 18°C | MuseumPests |
| Adult females | About 21 days at 18°C | MuseumPests |
| Egg to egg | Usually 4 to 6 months | UC IPM |
How long do moths live in the UK?
Temperature is the big factor, and it varies a lot from home to home. English Heritage, which looks after historic buildings across England, says clothes moths usually manage:
- about one generation a year in unheated buildings,
- about two generations a year in heated buildings,
- about three generations a year in very warm buildings.
So in a centrally heated home, you could have two rounds of egg laying a year. In a cold outbuilding, things move more slowly, but the larvae can also live longer.
Why the life cycle matters for getting rid of moths
Eggs survive many treatments
Eggs laid deep in a carpet or in a fold of fabric can hatch days after a spray visit, as the hatching times above show. This is why council treatments, such as those run by Lambeth, involve two visits spaced two weeks apart: the second visit catches the larvae that have hatched since the first.
Larvae can hide for a long time
Because larvae can live for many months, a quiet spell does not always mean the problem has gone. Keep checking hidden spots and keep a pheromone trap out to monitor. Our post on the signs of clothes moths explains what to look for.
Heat kills every stage
This is the main reason people choose moth heat treatment. Conservation guidance on MuseumPests, citing Strang (1992), says a short exposure at 55°C is enough to kill all life stages of insects. Eggs, larvae, pupae and adults all die at once, so there is no need to wait for eggs to hatch before the next round.
For smaller items at home, freezing is the cold equivalent: English Heritage and the BPCA advise -18°C for at least two weeks in a sealed bag. For a whole room, see our pages on heat treatment, moth fumigation and moth control, or check rough prices with the cost calculator.
We are a free matching service and do not treat anything ourselves. We find a local professional who does.
If the damage keeps coming back, ask for a free quote and we will find a specialist who covers your area.