How to tell if you have bed bugs

What a bed bug looks like

An adult bed bug is about 5 mm long, flat and oval, and reddish-brown, about the size of an apple seed. Some guides give 4 to 7 mm. The eggs are about 1 mm. Bed bugs hide by day and come out at night to feed.

Signs in the bedroom

Look for these signs, in the bed and around it:

• itchy, raised bites in lines or clusters on skin that is exposed in bed
• small blood spots on sheets or pillows
• dark-brown specks, which are droppings, on bedding and mattress seams
• pale shed skins
• eggs about 1 mm long in seams and crevices

Bed bugs hide in bed frames, mattress seams, furniture, skirting and behind pictures, so check beyond the bed. Use a torch and a stiff card to run along seams, and check the headboard and the back of the bed frame, where bugs often gather. Look again at night if you find nothing by day.

Bites: what they look like

Bites are raised and itchy, often in lines or clusters, and usually on skin that is out of the covers when you sleep. They usually clear within a week. See a GP if a bite is painful or swollen.

Bites alone prove nothing. Mosquito bites and flea bites can look similar. Many UK searches for bed bug bites return US pages, so use the NHS bed bug guide for UK facts.

Bed bug, flea or carpet beetle?

Fleas are smaller, at 1 to 3 mm, and their bites are usually below the knees. Carpet beetles are 2 to 4 mm, and the larvae are hairy. Neither is the same as a bed bug. If you find a bug, a clear photo or a sealed sample helps a pest controller identify it.

The idea that bed bugs live only in beds is a myth. They hide in furniture, skirting and behind pictures. They do not mean your home is dirty: they arrive on luggage, second-hand furniture and clothes.

How bed bugs get into a home

Bed bugs travel on luggage, second-hand furniture and clothes, which is why they are linked to travel, student moves and used furniture. Check your luggage when you return from a trip, and inspect second-hand furniture before it goes into a bedroom. Because homes are heated, bed bugs breed indoors all year, so a few can quickly become many.

What to do next

If you have found bed bugs, see bed bug treatment, the DIY guide and what it costs. Activity follows travel and tends to peak in late summer and autumn, and Rentokil reports confirmed activity up 44% a year from 2023 to 2025.