Bed bugs are small, flat, and expert at hiding. They spend most of their time tucked into cracks, seams, and crevices, emerging only at night to feed. If you suspect you have them, a thorough inspection is the first step. Here is how to do it properly.

What you are looking for

Adult bed bugs are about 5mm long, oval-shaped, and reddish-brown. After feeding they become darker and more swollen. You may also find:

• Dark spots: small black or brown dots on mattress seams, bed frames, and nearby surfaces. These are bed bug excrement.
• Blood stains: small rust-coloured smears on sheets or pillowcases, caused by bugs being crushed during sleep.
• Shed skins: pale, translucent husks left behind as nymphs moult through five growth stages.
• Eggs: tiny, white, and about 1mm long. Often found in clusters in seams and crevices.
• Live bugs: most visible at night with a torch, or during the day in heavily infested rooms.

Where to inspect

Work systematically through the room, starting closest to the bed and working outward. Use a torch and a credit card or similar tool to probe seams and gaps.

• All seams, tufts, and folds of the mattress and box spring
• The bed frame, headboard, and footboard, including screw holes and joints
• Behind and underneath bedside tables and drawers
• Along the edge of carpets and under rugs near the bed
• Behind picture frames and mirrors on nearby walls
• Inside electrical sockets and light switch covers
• In the folds of curtains and behind curtain rails
• Along the seams of upholstered furniture such as sofas and chairs

How bed bugs spread

Bed bugs do not fly or jump. They spread by hitchhiking on luggage, clothing, second-hand furniture, and bedding. Hotels, hostels, and holiday accommodation are common sources of infestation. They can also spread between flats in a shared building through wall cavities and under doors.

If you have recently stayed away from home or brought second-hand furniture into your property and then started noticing bites, bed bugs are a likely explanation.

Why professional treatment is necessary

Bed bugs are one of the most difficult pests to eliminate without professional intervention. They are resistant to many over-the-counter insecticides, and their ability to hide in tiny crevices means that surface sprays rarely reach the entire population. A single surviving pregnant female can restart an infestation.

Professional treatment typically involves a combination of residual insecticide applied to all harbourage sites, with follow-up visits to treat any newly hatched nymphs. Preparation by the occupant, such as washing and heat-drying all bedding and clothing, is an important part of the process.