Bed Bugs, Fleas or Scabies?
One bite tells you almost nothing. Where they are, how they are arranged, when they appear and who else has them — that is what identifies the cause.
Part of the Complete Insect Bites Guide.
Key fact: A single bite tells you almost nothing. What identifies the culprit is the pattern — how many, where on the body, whether they arrive overnight, and whether anyone else in the household has them.
Read the pattern, not the bite
People bring a photograph of one bite and ask what caused it. It is almost never answerable that way, because an individual bite from a bed bug, a flea and a mosquito can look identical — a red, raised, itchy bump.
What separates them is everything around the bite. Four questions do most of the work:
- How many, and arranged how? Scattered singles, tight clusters, or a line.
- Where on the body? Ankles behave differently from shoulders, and finger webs differently again.
- When do they appear? Overnight, or during the day.
- Is anyone else affected? Household spread narrows it considerably.
This guide is about working out which of the four common causes you are dealing with. If you have already identified an ordinary insect bite and want to know what to put on it, that is covered on our insect bites and stings page.
Bed bugs
Bed bugs feed at night on skin that is uncovered while you sleep — face, neck, shoulders, arms and hands. They do not live on the body; they live in the mattress seams, the bed frame, the headboard and nearby furniture, and come out to feed.
| Feature | What you see |
|---|---|
| Arrangement | Often in a line or a tight cluster of three or so, sometimes described as “breakfast, lunch and dinner” — the bug feeding, being disturbed, and resettling nearby |
| Where | Skin exposed above the covers: face, neck, shoulders, upper arms |
| Timing | New bites each morning; nothing new during the day |
| The room | Small dark spots on the sheet near where you lie (bed bug droppings), tiny shed skins, occasionally a sweetish musty smell in a heavy infestation |
| Travel link | Frequently starts after a hotel stay or second-hand furniture |
Bed bugs are not a hygiene problem. They occur in spotless homes and expensive hotels, they are not associated with dirt, and they do not transmit disease. They do need professional pest control, because household insecticides rarely clear an established infestation and the bugs can survive months between feeds.
The decisive check is the bed itself: strip it in daylight and look along the mattress piping, the seams and the joints of the frame.
Fleas
Flea bites concentrate on the lower legs and ankles, because fleas live in carpet, rugs and pet bedding and jump upward. They come in clusters of small, intensely itchy bumps, often with a tiny dark centre where the bite was.
- Almost always ankles and lower legs in adults; children crawling or sitting on the floor get them more widely.
- A pet in the house, or one that was recently, is the usual source — though fleas persist in carpet for months after a pet has gone.
- Classically after returning from holiday, when dormant fleas in the carpet are triggered by movement and warmth after an empty house.
- The pet may not look itchy. Check its fur for flea dirt — dark specks that turn rust-red on damp cotton wool.
Treating the animal alone does not work. The great majority of the flea population is in the carpet and soft furnishings as eggs and larvae, so the environment has to be treated at the same time.
Scabies
Scabies is not an insect bite at all — it is a mite living in the skin, and it behaves quite differently from anything that bites and leaves.
Three features separate scabies from bites: the itch is far worse at night and often intolerable; the rash favours finger webs, wrists, armpits, waist, buttocks and genitals rather than exposed skin; and it spreads through a household over weeks, because it passes by prolonged skin-to-skin contact.
The finding that confirms it is a burrow — a fine, slightly raised, greyish wavy line a few millimetres long, most often in a finger web or on the side of a wrist. Bites do not produce burrows.
Scabies needs specific treatment applied to the whole body, and everyone in the household needs treating on the same day whether or not they itch. Our guides to recognising scabies and the condition itself cover it properly.
Mosquitoes and midges
The default explanation, and usually the right one. Mosquito and midge bites are scattered singles or a few together on exposed skin — ankles, forearms, neck — with an obvious environmental link: an evening outdoors, still water nearby, warm damp weather, Scotland in summer.
They appear within minutes to hours of being outside rather than overnight in bed, and nobody else in the house wakes up with new ones unless they were outside too. Reactions vary enormously between people, which is why one person in a group is covered and another has nothing.
The four compared
| Bed bugs | Fleas | Scabies | Mosquitoes | |
|---|---|---|---|---|
| Where | Face, neck, shoulders, arms | Ankles and lower legs | Finger webs, wrists, waist, groin | Any exposed skin |
| Pattern | Lines or tight clusters | Clusters of small bumps | Rash plus burrows | Scattered singles |
| Timing | Overnight, every night | Any time indoors | Constant; itch worst at night | After being outdoors |
| Spreads to others? | Only if they sleep there | Anyone in the house | Yes — readily | No |
| Clue elsewhere | Spots on bedding, mattress seams | A pet, or carpet | Burrows; others itching | Recent time outside |
| Needs | Pest control | Treat pet and home | Prescribed treatment, whole household | Symptom relief only |
What to do about each
Whatever the cause, the itch is treated the same way — a cold compress, an antihistamine, and hydrocortisone 1% or mepyramine cream on the bites themselves. What differs is what you do about the source.
| Cause | The part that actually ends it |
|---|---|
| Bed bugs | Professional pest control. Wash bedding hot, but do not expect that alone to clear it |
| Fleas | Treat the animal and the environment together, and vacuum thoroughly and repeatedly |
| Scabies | Prescribed whole-body treatment, everyone in the household on the same day, repeated after a week |
| Mosquitoes and midges | Repellent, covering up at dusk, and treating the bites |
If bites become increasingly red, hot, painful or start to spread outwards over a day or two, that is a different problem — our insect bites and stings page covers what infection looks like and what to do about it.
Frequently Asked Questions
How can I tell bed bug bites from flea bites?
Location and timing. Bed bug bites appear on skin left uncovered in bed — face, neck, shoulders and arms — and arrive overnight, often in a line or a tight cluster of three. Flea bites concentrate on the ankles and lower legs, because fleas live in carpet and jump upward, and can appear at any time of day. Bed bugs also leave small dark spots on the sheets, which fleas do not.
Why do I get bites every morning but nobody else in the house does?
If the bites are only on skin exposed above the covers and appear overnight, bed bugs in your bed are the most likely explanation, and they would only affect whoever sleeps there. Reactions also vary enormously between people, so two people can share a bed and only one develop visible bites. Strip the bed in daylight and check the mattress seams and frame joints.
Are bed bugs a sign of a dirty house?
No. Bed bugs occur in immaculate homes and in expensive hotels, they are not associated with dirt or poor hygiene, and they do not transmit disease. They are usually introduced by luggage after travel or in second-hand furniture. They do need professional pest control, because household insecticides rarely clear an established infestation.
How do I know if it is scabies rather than bites?
Three things point to scabies: an itch that is far worse at night and often intolerable; a rash favouring the finger webs, wrists, armpits, waist and groin rather than exposed skin; and other people in the household developing the same itch over following weeks. The confirming sign is a burrow — a fine greyish wavy line a few millimetres long, most often in a finger web. Bites do not produce burrows.
Can I get flea bites if I do not have a pet?
Yes. Fleas survive in carpet and soft furnishings for months after a pet has left a property, and dormant fleas can be triggered by the warmth and movement of people returning to a house that has been empty. Bites appearing on the ankles shortly after moving into a new home, or after coming back from holiday, are a recognised pattern.
References
- NHS. Insect bites and stings. nhs.uk
- National Institute for Health and Care Excellence. Clinical Knowledge Summary: Insect bites and stings. cks.nice.org.uk
- National Institute for Health and Care Excellence. Clinical Knowledge Summary: Urticaria. cks.nice.org.uk
- Resuscitation Council UK. Emergency treatment of anaphylaxis. resus.org.uk
- DermNet. Papular urticaria, bullous insect bite reactions and urticaria. dermnetnz.org
- UK Health Security Agency. Bed bugs and public health. gov.uk
Medical disclaimer: This article is for informational purposes only and does not constitute medical advice. A severe allergic reaction to a sting is a medical emergency — difficulty breathing, swelling of the lips, tongue or throat, a widespread rash or feeling faint after a sting means calling 999 immediately. Always consult a qualified healthcare professional for diagnosis and treatment.