How to tell if you have fleas: bites, signs and where they hide

Fleas are small, fast and mostly hidden, so an infestation is often confirmed by its signs rather than by seeing the fleas themselves. Knowing what to look for, on your skin, on your pets and in the home, lets you catch a problem early, before it becomes established. Here is how to tell.

Flea bites on people

Flea bites are small, red and very itchy, and they have a tell-tale pattern: they tend to cluster around the ankles and lower legs (fleas live low, in carpets and skirting), often in little lines or groups of three or four, with a small red dot at the centre. They are not usually dangerous, but they itch persistently and can become irritated if scratched. Bites concentrated on the lower legs, appearing in groups, are a strong sign of fleas rather than another insect.

Signs on your pets

• Persistent scratching, biting or licking, especially around the base of the tail, belly and neck.
• Restlessness and irritation out of the ordinary.
• Flea dirt in the coat: tiny dark specks, best seen by parting the fur near the skin.
• In heavy cases, hair loss or scabbing from constant scratching.
• Occasionally, glimpsing the fast-moving fleas themselves.

Where fleas hide in the home

Only a small share of a flea population lives on the pet; the rest (eggs, larvae and pupae) sits in the environment. Look in pet bedding, carpets and rugs, along skirting boards, in floor gaps and cracks, and in upholstery and the pet's favourite resting spots. Flea dirt (flea droppings) shows up as dark specks in these places, and a damp tissue pressed onto them turns reddish-brown, because flea dirt is digested blood: a reliable confirmation.

Two simple tests

Two quick checks confirm fleas. Put on white socks and walk slowly across the carpet, especially in warm, shaded spots; jumping fleas show up against the white. And comb your pet over a sheet of white paper, then dampen any specks that fall: if they smear reddish-brown, it is flea dirt. If either test is positive, you have fleas in the home, and treating the pet alone will not clear them; see our flea treatment service and preparing your home for a flea treatment.

Frequently asked questions

• What do flea bites look like?

  Small, red, very itchy spots, usually clustered around the ankles and lower legs, often in lines or groups of three or four with a red dot at the centre. Bites concentrated low on the legs and appearing in groups point to fleas rather than another insect.
• How do I check my home for fleas?

  Look for flea dirt, dark specks that turn reddish-brown on a damp tissue, in pet bedding, carpets and along skirting. Wear white socks and walk the carpet to reveal jumping fleas, and comb your pet over white paper to check for flea dirt. Positive signs mean fleas are in the home, not just on the pet.
• Can you have fleas without seeing them?

  Yes. Fleas are small and fast, so infestations are usually confirmed by signs rather than by seeing the fleas: itchy bites on the lower legs, pets scratching, and flea dirt in bedding and carpets. Most of the population is hidden as eggs and larvae in the home.