Where Carpet Beetles Come From
Like carpet moths, it is the larvae that do the damage and they eat the same things — wool, silk, fur, feather and animal hair. The difference is the route in, and understanding it is what stops the problem recurring every spring.
Birds' nests in the eaves
An old nest is full of feather, down and dead material, which is ideal larval food. Barnet's 1920s and 1930s roofs have deep eaves and soffit boards that open up with age, and starlings and sparrows use them heavily. When the nest is abandoned the larvae leave it, drop into the roof space and work downwards into the rooms below.
This is why carpet beetle damage in a Barnet house so often starts in an upstairs room rather than downstairs, and why clearing the nest and closing the eaves matters as much as the treatment itself.
Loft insulation and stored textiles
Once in the roof space they carry on through anything woollen that has been put away — blankets, old clothes, rolled rugs, felt and the boxes of things that live in a Barnet loft for twenty years. Long-term storage is where the population builds up unnoticed.
Telling them from carpet moths
The larva is the giveaway. A carpet beetle larva is short, plump and covered in stiff brown bristles, and it curls up when disturbed; a carpet moth larva is smooth and cream and drags a silken case about. The adult beetle is small, round and mottled, and is most often found dead on a windowsill in spring.
Signs of carpet beetles
- Bristly brown "woolly bear" larvae, or the shed skins they leave behind
- Small round mottled beetles on windowsills, usually in spring
- Clean-edged holes in wool carpet, blankets or stored clothing
- Damage starting in an upstairs room or a room under the eaves
- An old bird's nest visible at a soffit or under the roof edge
