Carpet beetles are the pest people most often mistake for something else — usually woodworm, clothes moths or 'just a bit of wear'. The damage is similar to moth damage but with a different pattern: small, scattered holes rather than concentrated bald patches, and tiny brown shed skins along skirting boards or in the bottom of drawers. They're active across the UK all year, but every spring there's a noticeable surge as adults emerge to mate and lay eggs.
The spring surge explained
Adult carpet beetles are 2–4mm, oval, mottled brown and cream, and they're drawn to daylight. In April and May they leave the dark places where the larvae have been feeding and gather on window sills trying to get outside to pollen and nectar — which is often the first time a homeowner notices them. While the adults are at the window, the larvae (often called 'woolly bears' for their bristly appearance) carry on feeding in the carpet, wardrobe or loft insulation.
Common UK hotspots
- Bird and squirrel nests in lofts, eaves and chimneys — by far the most common reservoir.
- Old wool carpet under heavy furniture that's never been moved.
- Natural-bristle brushes, taxidermy, dried flower arrangements and feather pillows.
- The fluff and pet hair that collects under beds and behind wardrobes.
Breaking the cycle
Vacuuming alone is rarely enough because larvae cling on with tiny hooked hairs. Effective control means finding and removing the reservoir (very often an old bird's nest in the loft), then treating carpets and harbourages with a residual insecticide so any newly hatched larvae die before they can feed and breed. If you keep finding small beetles on south-facing window sills in April, it's worth getting the loft checked — that's almost always where the population is coming from.