How to tell if you have bed bugs: signs, bites and where to look in a London flat

The surest signs of bed bugs are physical: live bugs about 5mm long, hollow shed skins, pearly white eggs about 1mm long, and dark spotting along mattress seams and bed frames. Bites on their own never confirm bed bugs, because fleas, mosquitoes and mites leave similar marks. If you find any of the physical signs, leave everything where it is and book an inspection.

What are the five signs of bed bugs?

Any one of these is worth a slow check with a torch.

• Live bugs. The NHS describes adults as about 5mm long and dark yellow, red or brown; most people say apple pip. Unfed bugs are paler, and the young are almost colourless, so a tiny translucent insect counts.
• Shed skins. Each bug moults five times on the way to adulthood and leaves a light brown casing behind, in the places where it rests rather than where it feeds.
• Eggs. Pearly white, about 1mm long, glued into seams, joints and cracks, usually in small clusters.
• Dark spotting. Digested blood left as black or dark brown dots, like the mark of a biro, on mattress piping, the bed base, the back of the headboard and nearby skirting boards.
• Blood spots. Small rusty smears on sheets where a fed bug was squashed. Westminster Council also lists a sweet, almond-like smell in heavy infestations.

What do bed bug bites look like?

Bed bug bites are raised, itchy and often in a line or a small group, usually on skin left uncovered at night such as the face, neck and arms. The NHS bedbugs page adds that on black or brown skin they look brown, red or purple and are harder to see, and says when to see a pharmacist or GP; follow that page for the medical side.

Two things make bites poor evidence. The skin reaction can be delayed by up to two weeks, especially the first time, and some people do not react at all, which is why one partner can be covered in bites while the other has nothing. The European code of practice says plainly that bites should never be treated as conclusive, because midges, mosquitoes, fleas, lice and scabies mites cause similar marks.

Bed bugs or fleas?

The quickest cue is where the bites are. The NHS guide to insect bites and stings describes flea bites as large, red, raised groups usually found below the knees, while Lambeth Council notes that bed bug bites are spread fairly evenly across the body. Bites concentrated on the ankles and shins point to fleas, especially if a pet has recently moved in or out.

Where should I look for bed bugs in a flat?

Start at the bed and work outwards, because bed bugs hide within a few metres of where someone sleeps. They climb wood, paper and plaster but not smooth polished surfaces, so they favour fabric, timber and cracks.

• Mattress seams and piping, the label, and the underside of the mattress.
• The bed base, especially inside a divan, and every joint and screw hole of a frame.
• The headboard, front and back, and the wall behind it.
• Skirting boards, the gap beneath them, and loose carpet edges.
• Plug sockets and light switches near the bed, picture frames and mirrors, and under loose wallpaper.
• Bedside drawers, curtain pleats and clothes left on the floor.
• The arm joints of a sofa or armchair if someone naps or sleeps there.

Check at night if you can. Bed bugs feed in the dark, often just before dawn, and are drawn by the carbon dioxide you breathe out, so a torch check after lying still with the lights off for a quarter of an hour sometimes shows what a daytime search misses.

How do bed bugs get into a London flat?

They are carried in, or they walk in from next door. The NHS lists luggage, clothing and second-hand furniture as the routes to watch, and every holiday, house move, short let and student term brings suitcases into bedrooms. A clean flat is no protection; infestations are confirmed in very clean accommodation too.

In converted Victorian terraces, mansion blocks and purpose-built estates they also travel between flats along cables and pipe runs, through wall voids and under doors. If a neighbour has had treatment, or you live in an HMO, check even if you have not travelled. The Tube has never had a confirmed case: TfL received 35 sighting complaints in October 2023 and none turned out to be bed bugs.

How common are bed bugs in London?

Common, and rising. Council pest control services visited 8,864 London homes with a bed bug problem in 2023, up about a fifth on the year before, according to an insurer's Freedom of Information request reported in April 2024. Across the UK, confirmed bed bug activity rose by an average of 44% a year between 2023 and 2025, counting only cases a technician verified on site.

A national pest control firm's call-out map for the twelve months to October 2026 puts Islington (N1) first in London, with Battersea (SW11), Tooting (SW17) and Kilburn (NW6) among the busiest districts and the West End (W1), Westminster (SW1) and Bloomsbury (WC1) not far behind. Its own caveat is that these are jobs attended rather than confirmed infestations, and its explanation is dense flats, shared housing and a fast-moving rental market. Calls peak from late summer into October after the holiday season, but development only stops below 13°C, so a centrally heated flat supports bed bugs all year; for the record, the Paris scare of October 2023 raised London council visits by less than 3%.

What should I not do if I find bed bugs?

Do not move rooms, do not throw out the bed, and do not spray anything.

• Keep sleeping in the same bed. Moving to the sofa or a spare room draws the bugs after you and turns a one-room problem into two.
• Leave the mattress and furniture where they are. Carrying a mattress through the flat sheds bugs and eggs, and the bed is rarely the only harbourage, so a new one is colonised within weeks.
• Do not use shop-bought sprays, foggers or essential oils. The NHS warns that bed bugs may resist some insecticides and that self-help is unlikely to remove them completely; sprays scatter survivors into walls and adjoining rooms, foggers cannot reach the cracks, and a sub-lethal dose breeds tougher bugs.
• Do not bag up and launder everything yet. Wait for the technician's written preparation list, so that nothing leaves the room unsealed.

What happens at a professional bed bug inspection?

A proper inspection confirms the species, maps every harbourage, and only then produces a quote. The BPCA code of practice says a full on-site survey is essential before any reliable quotation, that pesticides must not be used if no evidence is found, and that the quote must state which rooms will be treated, how many visits are planned and what happens if control is not achieved after the last one.

Our technician strips the bed, lifts the mattress and base, takes the headboard off the wall, checks skirting, sockets and picture frames, and asks about adjoining rooms and neighbours. Where there is evidence, you get a fixed price for a course of bed bug treatment using dry steam and a residual insecticide over at least two visits, with a written six-month guarantee, subject to the site survey. Where there is none, we talk about monitoring rather than sell you a treatment you do not need.

What to do next

If you have found any of the signs above, leave the room as it is. Call Pest Stop Control on 020 3411 2329, Monday to Saturday 8am to 7pm, for a free inspection survey, often the same day. We cover central, west, north-west, north and south-west London and the TW postcodes, including the busier districts around Battersea, Tooting and Kilburn, or you can send us the details online.