Identification Guide

SIGNS OF A BED BUG INFESTATION

A field-tested guide to spotting bed bugs early — in your bedroom, your hotel room, your tenant's flat or your child's halls of residence. The earlier you catch it, the smaller the treatment, the lower the cost and the less the infestation has spread.

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1. Bites — the unreliable first clue

Bites are usually the first thing people notice, but they are also the least reliable single piece of evidence. About 30% of bitten adults show no skin reaction at all; another 30% react strongly and immediately; the rest fall somewhere in between, often with a delayed reaction that appears 24–48 hours after the bite. The classic pattern is a straight line or tight cluster of itchy red welts on skin that was exposed during sleep: the arms, neck, shoulders, ankles, back. Pest control technicians call it "breakfast, lunch and dinner" — three bites in a line where the insect fed, walked a few mm, fed again.

Crucially: bites alone are not enough to call a bed bug job. We always ask for a second piece of evidence before mobilising the heat rig. Skin reactions to fleas, mites, mosquitos, hives and contact dermatitis can all look similar.

2. Blood spots on the sheet

When a bed bug feeds and is then rolled onto by the sleeper, it is crushed and leaves a small smear of partially digested blood on the sheet. These look like rust-coloured dots, often in the area where your hips, shoulders or feet rest. A handful of fresh blood spots on a clean sheet is one of the most specific early-stage signs of an established infestation.

3. Faecal pinpoints

Bed bug droppings are pinpoint dark spots about 0.5–1mm across — they look like a black biro tip touched the fabric. The classic locations are along the piping of the mattress seam, on the box spring or divan base near a leg, on the underside of the headboard, on the wall behind the headboard, and on the bedside skirting. They smear rust-red when rubbed with a damp white tissue (the digested blood reactivates). A line of faecal pinpoints along the mattress seam is essentially diagnostic.

4. Shed skins (casings)

Bed bugs moult five times between hatching and adulthood. Each moult leaves a translucent, pale tan shell — a perfect insect outline, hollow and brittle. Casings collect in the same harbourage spots as the live insects: mattress seams, joints of the bed frame, behind picture frames, inside the bedside drawer. The presence of multiple sizes of casings means a breeding population — not a single hitchhiker.

5. Eggs and eggshells

1mm long, pearl-white, glued in tight clusters into seams and joints. Almost invisible without a magnifier on pale fabric, obvious on dark fabric. Empty eggshells (hatched) collect alongside the cast nymph skins. If you can see eggs you are looking at an established breeding population that has been in the property for at least three weeks.

6. Live insects

Adult bed bugs are 4–5mm long, flat, oval, reddish-brown — about the shape and size of an apple seed. After feeding they engorge and lengthen, becoming darker and almost cigar-shaped. Nymphs are smaller (1–4mm), pale tan, and almost translucent before their first feed. They are nocturnal and photophobic, so the easiest way to spot them is to pull back the sheet at 2am with a torch.

Where to actually look

A trained technician inspects in this order, because this is where evidence concentrates by frequency:

  1. Mattress seams, tags, piping and underside.
  2. Box spring / divan staples and dust cover.
  3. Headboard joints, brackets and the wall directly behind.
  4. Bedside drawer runners and undersides.
  5. Skirting boards within 1m of the bed.
  6. Electrical sockets and light switches in the bedroom.
  7. Curtain hems, picture frame backs, smoke alarms.
  8. Sofas — under cushions, inside the recliner mechanism, along the inside seams.
  9. Suitcases and travel bags stored in the bedroom.

What to do if you find any of this

Three rules:

  1. Stop sleeping in another room. A common reaction is to abandon the bedroom and sleep on the sofa. The bed bugs follow you within days, and now you have two infestation sites instead of one. Stay where you are until treatment.
  2. Stop bagging up clothing and storing it elsewhere. Eggs go with the bags. Leave clothing on the bedroom floor — heat will treat it in place.
  3. Take photos and call us. Two or three close-ups of the insect, casing or blood spot is enough to confirm species and quote you a fixed price. We can usually be on site the same day across London and the M25.

Where we deliver this service

We respond across London and the Home Counties on the same day. Click any location below for postcode-level coverage, response times and pricing for that exact area.

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Frequently asked questions

What is the first sign of bed bugs?

For most people it is bites — small itchy red welts, usually in a line or cluster, that appear overnight on skin exposed during sleep. Bites alone are not proof (some people don't react). The next things to look for are tiny dark blood spots on the sheet near where you slept, and 1mm dark faecal pinpoints on the mattress seam.

What do bed bug bites look like?

Itchy red welts, often with a darker centre, typically 5–15mm across. Bites commonly appear in clusters or in a straight line of 2–4 (the 'breakfast, lunch and dinner' pattern). Reactions vary wildly between people: 30% of bitten adults show no skin reaction at all and only discover the infestation through other evidence.

What do bed bug droppings look like?

Pinpoint dark spots — 0.5–1mm — that look like someone touched the fabric with the tip of a black biro. Concentrated along mattress seams, on the box spring, on the headboard and on bedside walls. They smear rust-red when rubbed with a damp tissue (digested blood).

What does a live bed bug look like?

Adult: 4–5mm long, flat, oval, reddish-brown, six legs, antennae. About the size and shape of an apple seed. After feeding they engorge and lengthen, becoming darker and almost cigar-shaped. Nymphs are smaller (1–4mm) and pale tan to translucent.

Is there a bed bug smell?

Heavy infestations have a faint sweet, musty, almond-like smell from bed bug alarm pheromones. You will not smell it at the early stage — by the time the smell is obvious you are looking at hundreds of insects.

What should I do if I think I have bed bugs?

Stop sleeping in the affected room (you will only spread them) and stop bagging up clothing into other rooms. Take close-up photos of any insect, casing or blood spot, and call us. If you can see live insects, you do not need an inspection — you need treatment, and we can usually be on site the same day.

Related guides

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