Adult beetle: 2–3 mm
Larva: 4–5 mm
The adult beetle is around 3 mm long. The museum beetle is almost round, dark in colour and its elytrons have shapes formed by lighter hair.
The larva is around 4 mm long, brown, has thick hair and a V-shaped tuft of hair at the end of its body. As with the adult beetle, it pretends to be dead when touched. Close relatives of museum beetles may also reside in indoor spaces, for example, a species with yellow shapes on its elytrons.
The female lays eggs in bird nests and dry carcasses. The larvae eat feathers and hair, as well as dried insects. The beetle eats pollen. If there are bird nests in the eaves of the house, the larvae may crawl indoors during autumn and hibernate in the rooms. During the spring, they will gather near the windows, in an attempt to return to nature.
The larvae harm textiles and furs by eating small holes into them or by cutting the hairs. They are also attracted by collections of insects or animals. Damages are usually minor in apartments.
Prevention and extermination
Birds’ nests and dead rodents should be removed from the attic, the eaves, cellar and chimneys. If necessary, they are exterminated in the same way as any other textile pests.