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 and some people show nothing.
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 — apple-pip sized. 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 Kenton →Worth being clear about, because bites cause a great deal of unnecessary alarm and occasionally a great deal of unnecessary complacency.
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 when in the garden 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 |
In a family house with a dog or cat, fleas are the far more common answer and the ankle pattern is the tell.
Read nextHow Do You Get Rid of Bed Bugs in a Kenton Home? →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.
Bitten outdoors instead? A wasp nest is £90 fixed cost in Kenton, 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 at all, and no doctor can diagnose bed bugs from a bite.
In a house with a pet, very possibly — flea bites are typically on the ankles and lower legs.
Yes, early on. That is why the dark spots matter more than the insects.
Check every joint on a bunk bed, the under-bed drawers, the headboard and the wall behind it. Children often do not report bites.
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.
Prefer to talk? Call 0203 151 6640 or WhatsApp us.
