Carpet beetle

How to recognise it

These are the features that identify a carpet beetle. Each one is described in words so the identification works without the diagram.

1. Adults are small, rounded, almost domed beetles 2 to 5 mm, mottled in black, white, and orange scales, or uniformly black depending on species.
2. Larvae are elongated, carrot-shaped, and densely covered in stiff bristles, often with a tuft of longer hairs at the rear — bed bugs are flat, oval, and hairless, which is the decisive difference.
3. Larvae leave behind shed skins that retain the bristly shape, unlike the smooth flat husks bed bugs leave.

What it leaves behind

• Irregular grazed damage to wool, silk, feathers, and animal-based materials, often under furniture and along carpet edges.
• Bristly shed skins accumulating in undisturbed areas, in air vents, and beneath heavy furniture.
• Adults found at windowsills, since they fly toward light.

Why an infestation persists

Larvae feed on keratin — wool, silk, feathers, hair, and dried animal matter — while adults feed on pollen outdoors and enter through open windows or on cut flowers. Damage is done entirely by the larvae, so finding adults at a window is a signal to look for larvae elsewhere.

Where it occurs

Throughout the United States.

Where to look for it

• Along carpet edges where they meet the skirting, and under the edge of a rug that is rarely lifted.
• Beneath and behind heavy furniture that has not been moved in a year.
• Inside air vents and ducts, where lint and hair accumulate.
• Wool, silk, cashmere, and fur garments in storage, especially items put away soiled.
• Taxidermy, felt on piano hammers, natural-bristle brushes, and dried flower arrangements.
• Old bird or rodent nests in a chimney, soffit, or wall void, which are a common overlooked larval food source.

When you see it, and why

Adults appear indoors in spring and early summer, most visibly at windowsills because they fly toward light on their way outdoors to feed on pollen. That is the useful signal: adults at a window mean larvae somewhere else in the property, since the damage is done entirely by the larval stage. Larval feeding continues year-round in a heated building.

What getting the identification wrong costs you

This is the most common false bed bug alarm, and the relief is warranted: carpet beetle larvae do not bite and do not feed on people, though the bristles cause skin irritation in some people, which sustains the confusion. Bristly and carrot-shaped is a carpet beetle; flat, oval, and hairless is a bed bug. Getting this right can save weeks of unnecessary distress and a treatment nobody needed.

What a professional actually does

The useful contribution is finding the larval food source, which is frequently not in the room where the damage appeared — an old bird nest in a soffit, accumulated lint in a duct, or a forgotten wool item in storage. Ask what the inspection will cover beyond the affected room. Thorough vacuuming of edges, beneath furniture, and in vents does much of the real work and is largely labour you can supply yourself.