Can fleas live on people?

Which flea is biting you

Clackmannanshire Council counts about 60 kinds of flea in Britain. Three bother people most: the cat flea, the dog flea and the human flea. The cat flea is by far the most common, and it bites dogs and people as well as cats, usually on the lower legs and ankles.

Knowsley Council says human fleas are now very rare in the UK, largely because of better hygiene and living standards. So if you are being bitten at home, the flea is almost certainly a cat or dog flea, even if you do not own a pet.

Adults are 1 to 4 mm long, reddish-brown, flattened from side to side, with long back legs for jumping.

Why they bite you but do not settle on you

A cat or dog flea is made for life in a furry coat, where it feeds, mates and lays eggs. Skin with little hair suits it far less well. On a person it jumps on, feeds and drops off, or is brushed away by clothes and washing.

Most of the fleas in a home are not on anyone at all. Knowsley Council notes that a female can lay up to 50 eggs a day and that most fall off the pet and hatch wherever they land. That means carpets, rugs, sofa cushions, beds and the pet's own bedding. You meet the young fleas when you walk across the floor, which is why bites gather around the ankles.

Bitten with no pet in the house

This is common, and there are three usual reasons.

• You moved into a home where a pet lived. Plymouth City Council says flea cocoons can stay dormant for two years or more and are woken by the vibration of footsteps, and that fleas often lie dormant in empty homes.
• A visiting animal brought them. A neighbour's cat that comes in, or a dog that stays for a weekend, can leave eggs behind.
• It is not fleas. The NHS says flea bites usually come in groups below the knees. Bites on the face, neck and arms after a night in bed point to bed bugs instead. Plymouth adds that office workers who report bites are often feeling static electricity, not insects.

If you have not found a flea, the flea identification guide explains the paper test for flea dirt.

How long fleas wait in a home

The timings for egg, larva and adult are Clackmannanshire Council's. The cocoon is the hardest stage to clear: it protects the flea from household sprays and waits until something walks past.

Do flea bites make you ill?

Knowsley Council says fleas do not pass any serious illness to people, but the bites can be very irritating. Plymouth says the saliva can cause raised, itchy spots in clusters or lines that stay itchy for several weeks, and some people react more strongly than others.

A pharmacist can suggest something for the itching. The NHS says to call 111 if symptoms get worse, and 999 if the lips, mouth, throat or tongue suddenly swell or someone is struggling to breathe.

Clearing them for good

Treat the pet and the house together, or the fleas return. Ask your vet about the pet. In the home, vacuum floors, sofas and the pet's sleeping places often, empty the vacuum outside, and wash bedding hot. Our DIY flea guide sets out the steps.

After a spray treatment, follow the instructions on vacuuming. Knowsley advises not vacuuming for at least 10 days so the insecticide can reach fleas as they hatch.

If bites carry on after two to three weeks, book flea treatment, and check what it costs. Many councils treat fleas for a fee. If you rent and the fleas were there when you moved in, Shelter's advice is that your landlord should deal with them; if your own pet brought them, expect to pay.