Carpet beetles are small insects belonging to the Dermestidae family. They are common household pests that cause significant damage to items made of natural fibers. Identifying an infestation requires understanding the distinct visual characteristics of both the adult and larval stages, as well as the physical signs they leave behind.
The Appearance of Adult Beetles
Adult carpet beetles measure between 2 and 4 millimeters in length, comparable to the size of a pinhead. Their body shape is oval or rounded, often resembling a tiny ladybug, though they are much less conspicuous. They are not known for rapid movement.
The coloration of the adult stage varies significantly depending on the species. Black Carpet Beetles are a uniform shiny black or dark brown. Varied Carpet Beetles display a mottled or speckled pattern created by a mix of white, yellow, and orange or brown scales, giving them a calico-like look. Because adults fly and are attracted to light, they are frequently seen near windowsills.
The Appearance of Larvae
The larval stage is responsible for the damage and is visually distinct from the adult insect. Larvae are elongated and segmented, often described as tiny, fuzzy worms. When fully developed, they reach a length of 4 to 5 millimeters, making them slightly larger than the adults.
Their body color ranges from tan or light brown to reddish-brown, sometimes featuring lighter stripes along their backs. The most defining feature is the dense covering of bristles or hair, which gives them a distinct “woolly bear” appearance. Larvae are slow-moving and tend to curl up or remain motionless when disturbed.
Visual Evidence of an Infestation
Even if the insects are not immediately visible, they leave behind several visual cues. The most common sign is the presence of shed skins, or exuviae, which the larvae leave behind as they grow. These casings are light brown or translucent, dry, and hollow, appearing like empty, brittle shells.
Shed skins are usually found where larvae are actively feeding, such as under furniture, along baseboards, or within folds of stored fabric. Another key indicator is the appearance of fecal pellets, which look like tiny specks roughly the size of table salt. These droppings are typically black or brown, with color varying based on the material the larvae have been eating.
Damage to materials is the most destructive visual evidence, appearing as irregular holes or thinning, bald patches in items made of natural fibers like wool, silk, or fur. Unlike the scattered damage caused by clothes moths, carpet beetle damage is often concentrated in one area, usually in hidden locations like the seams of upholstered furniture or the underside of rugs.