How to tell bites apart
Bites on their own are unreliable evidence. People react differently, and some don't react at all. The pattern and timing help, but the strongest clues are around the house: in the bed, on the carpet, on your pets.
| Cause | Pattern | Where on the body | When | The giveaway |
|---|---|---|---|---|
| Bed bugs | Lines or tight groups | Arms, neck, shoulders, face | Overnight | Ink-like dots and blood spots on the mattress |
| Fleas | Small clusters | Ankles and lower legs | After sitting or with pets | Jumping specks, pets scratching |
| Mosquitoes and midges | Single raised bumps | Exposed skin | Evenings, summer | Buzzing at night, time outdoors |
| Bird mites | Clusters of tiny spots | Anywhere | After birds leave a nest | A nest near a window or in the roof |
| Carpet beetle larvae | Rash, not true bites | Where skin touches bedding or carpet | Any time | Hairy larvae and shed skins |
Bed bug bites
Bed bugs feed at night on skin left uncovered: arms, shoulders, neck and face. Bites often appear in a line or a tight group. Check mattress seams, the bed frame and the headboard for live bugs, pale shed skins and black dots that smear like ink. Our bed bug guide walks through a proper check.
Flea bites
Fleas jump onto legs from carpets and sofas, so bites cluster around the ankles. If you have a cat or dog, check their fur for dark specks that turn reddish on damp paper. If you've just moved in, the previous occupants' pets may have left a flea problem behind. See our guide to fleas.
Could it be a spider?
Spider bites in the UK are rare and usually happen when someone presses on or handles a spider, often a false widow in a shed, window frame or garden furniture. A spider bite is usually a single painful spot rather than a group. See our guide to house spiders and false widows.
When it might not be bites
A lot of itchy skin has nothing to do with insects. Heat rash, allergic reactions, eczema and a change in washing powder are all common. If you can't find any evidence of pests, it's worth showing a pharmacist before spending money on treatments.
Questions people ask
Why am I the only one getting bitten?
People react to bites very differently. Partners and housemates may be bitten too but show no marks. That's why evidence around the house matters more than bites.
Can I see bed bugs with the naked eye?
Yes. Adults are about the size of an apple seed. Young bed bugs are smaller and paler, and easiest to spot with a torch along mattress seams.
Should I use a bug bomb or fogger?
We don't recommend them. They often scatter bed bugs into new hiding places and miss fleas deep in carpets.
When should I see a doctor about bites?
Speak to a pharmacist first for itchy bites. Contact NHS 111 if a bite looks infected, is spreading, or you feel unwell. Call 999 for swelling of the face or throat or difficulty breathing.