Carpet beetles are a 3 mm–long beetle that can be a serious household pest. It feeds on natural fibers and can damage carpets, furniture and clothing.
The larval form is known as a woolly bear.
Two species of carpet beetles are indigenous in New Jersey. Both the varied and black carpet beetle larvae pose as a serious pest.
The larval form are roughly 0.16–0.20 inches in length. The body is covered in a pattern of alternating light- and dark-brown stripes. The body is usually wider at the back than at the front and also bears 3 pairs of hair tufts along its rear abdomen that can be used for self-defense.
Adults range from 0.07 to 0.14 inches in length. Their dorsal surface is either black (black carpet beetle) or mottled colors, whitish to yellowish-brown (varied carpet beetle).
Carpet beetles have an unusual life cycle for an insect, developing from larvae to adult in 1–3 years, depending on the environmental conditions. Larvae hatch from eggs in the spring and early summer, often in the nests of birds or around stored fabrics. Larvae feed on natural fibers throughout their development, eventually experiencing a dormancy period prior to pupation into the adult stage. The length of the dormancy appears to depend on environmental factors.
Adults emerge between late May and early August, flying to and feeding on the pollen of flowering plants. During this period, mating occurs, eggs are laid, and the cycle begins again.
The larvae of carpet beetles is a common household pest. Adult beetles usually lay their eggs in air ducts, in closets, under furniture, or under baseboards. Once hatched and until they pupate into adults, the larvae hide in dark, undisturbed areas and feed on organic material. The larvae are thus responsible for the damage of various items, such as furniture, clothing, blankets, furs, and carpets. Collections of specimens, especially of insects, are also vulnerable to attack, making carpet beetles a common pest in museums. Infestations can be prevented by regular vacuum cleaning, dry cleaning or airing clothing outside, placing moth balls in closets, and removing abandoned bird and insect nests attached to the building. Signs of an infestation include the presence of damaged articles, molted larval skins in dark areas, and an abundance of adult beetles near windows.