Bites tell you very little. Dark spots on a mattress seam tell you almost everything. Here is where to look and what you are looking at.
Dark spots on the mattress seam or bed frame are the most reliable sign — digested blood, like a fine felt-tip mark that does not brush off.
Then live insects, shed skins and small blood smears on the sheet. Bites are the least reliable evidence, because reactions vary enormously.
A torch and a card to run along a seam is the whole toolkit. Look in the joints, not on the surfaces.
| Sign | What you are looking at |
|---|---|
| Dark spots | Digested blood. Fine felt-tip marks on the seam that do not brush off |
| Live bug | Flat, oval, reddish-brown, 4–5mm. Rounder and darker after feeding |
| Shed skins | Pale translucent insect shapes; they moult five times |
| Eggs | About 1mm, pearly white, cemented into a crevice — hard to see |
| Blood smears | Small rust marks on the sheet where one was crushed |
| Smell | Sweetish, musty — only in a heavier case |
See our full bed bug treatment service, published room prices and preparation guidance.
View Bed Bug Control Edgware →If a bite reaction is severe, spreading or infected, that is a matter for a doctor. What it is not is a way of confirming what bit you.
| What you are seeing | Possibly |
|---|---|
| Bites mainly on ankles and lower legs, and there is a pet | Fleas |
| Itchy rash, no bites found, bristly larvae in the carpet | Carpet beetle larval hairs |
| Bites only outdoors or at dusk | Mosquitoes or midges |
| Itching with no marks at all | Dry skin, fabric, detergent — a doctor's question |
| Bites in a line, plus dark spots on the mattress seam | Bed bugs |
Worth doing in a converted property or a terrace.
Yes, early on. That is why the dark spots on the seam matter more than the insects.
Mostly, but a heavy infestation will feed in daylight.
Yes, particularly one that gets slept on.
Stung outdoors instead? A wasp nest is £90 fixed cost in Edgware, guaranteed.
Dark spots on the mattress seam or bed frame — digested blood, like fine felt-tip marks that do not brush off.
The mattress seam and piping all the way round, then the bed base, frame joints and screw holes, and the headboard.
Flat, oval, reddish-brown and about 4–5mm — apple-pip sized. Rounder and darker after feeding.
No. Reactions vary enormously, some people show nothing, and no doctor can diagnose bed bugs from a bite.
In a home with a pet, very possibly — flea bites are typically on the ankles and lower legs.
In a converted property or terrace it is worth looking at skirting joints and service penetrations, though finding nothing does not rule it out.
Yes, early on. That is why the dark spots matter more than the insects.
Photograph it, do not strip everything, do not move rooms, do not throw the bed out, and do not spray it.
Photograph the mattress seam and send it. That usually settles it before anyone visits.
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