Quick facts
- Common species
- Cat flea (Ctenocephalides felis), which also bites dogs and people
- Adult size
- About 1.5 to 3 mm, dark brown, jumps long distances
- Life cycle
- Egg, larva, pupa, adult; pupae can lie dormant for weeks to months
- Hot spot
- Pet beds, carpets, rugs, sofas and floor gaps
- Peak
- Warm, humid weather, although heated homes can have fleas all year
How to identify fleas
Fleas are tiny, wingless insects that jump onto hosts to feed on blood. Adults are only a small part of the problem. Eggs fall off pets into carpets and cracks, larvae feed on debris, and pupae wait in a protective cocoon until they sense vibrations or warmth, which is why fleas can seem to appear suddenly in a home that has been empty for a while.
If your pet scratches, or you have small itchy bites around the ankles and lower legs, fleas are likely. You can check by combing the pet over a white towel: small black specks that turn red when damp are flea dirt, which is digested blood.
Signs of fleas in your home
- Small itchy bites on ankles and lower legs, often in clusters
- Pets scratching, licking or biting at their fur
- Flea dirt (black specks) in pet fur or bedding that turns red on a damp tissue
- Fleas jumping on pale socks or carpets
- A sudden flea outbreak after moving into a property or returning from a holiday
Risks and damage
Flea bites cause itching and skin irritation, and some people and animals develop allergic reactions. Fleas can transmit tapeworms to pets and can cause anaemia in young or small animals if numbers are high. Heavy infestations can be distressing for the whole household.
Why fleas come into properties
A pet bringing them in, secondhand furniture, wildlife such as foxes or rodents near the house, or a previous occupier's pet. Pupae in carpets can stay dormant, so fleas can appear after a house has been empty.
How to prevent fleas
- Treat all pets regularly with a vet-approved flea product
- Wash pet bedding on a hot wash weekly during an outbreak
- Vacuum carpets, rugs, sofas and floor edges often, and empty the bag or bin outside
- Check second-hand furniture and bedding before bringing them into the home
- Reduce wildlife access to underfloor spaces and sheds
Professional flea treatment by Southwark Pests
Effective flea control has three parts: treating the pets with vet-recommended products, treating the house and washing soft furnishings, and treating carpets and floor edges with an insecticide that includes an insect growth regulator so that eggs and larvae stop developing. Vacuuming before treatment helps and triggers pupae to hatch, so that they meet the treatment.
Expect to see a few fleas for one to two weeks after treatment as pupae emerge. A second visit may be advised. Do not clean carpets deeply straight after treatment as this can remove the residual product.
When to call a professional
Call a professional if bites continue after treating the pets, if you have a large infestation, if you have a baby or vulnerable person in the home, or if you are moving into a property that has had fleas.
Flea treatment across Southwark and London
We often treat fleas in homes after a new pet arrives, after moving into a property where the previous occupants had animals, or in flats where foxes or cats have been sleeping under decking or in the garden. We cover South London, Central London (the City, the West End and Westminster), East London out to Stratford and Newham, and nearby parts of Kent, from our base at South Dock Marina in SE16. A standard visit is £90, and you can book online or call 020 8050 2022.
- Southwark
- Bermondsey
- Peckham
- Camberwell
- Rotherhithe
- Lambeth
- Brixton
- Lewisham
- Greenwich
- Bromley
- Bexley
- Kent
- Central London
- City of London
- Westminster
- East London
- Tower Hamlets
- Hackney
- Newham
- All areas
Flea treatment: questions and answers
My pet has been treated but I still have fleas. Why?
Most fleas are in the environment as eggs, larvae and pupae. Pets must be treated and so must the home, or new adults keep hatching.
How long until the fleas are gone?
Often two to three weeks as the remaining pupae hatch and die. A follow-up visit may be needed in heavy cases.
Do I need to leave the house during treatment?
Usually yes for a few hours. Your technician will tell you about re-entry time and what to do with pets, food and bedding.
Can fleas live on people?
They bite people but do not live on them. They prefer animals with fur or feathers.
Where do fleas come from if I have no pets?
From previous occupiers, wildlife, second-hand items or visiting animals.
Will vacuuming help?
Yes, regular vacuuming removes eggs and larvae and stimulates pupae to hatch, which helps the treatment work. Empty the vacuum outdoors afterwards.
Related pages
- Fleas, bites and pets
- Preparing for flea treatment
- Is pest control safe for pets and children?
- Fox deterrence
This page is general information, last reviewed on 19 October 2026. It is not a substitute for an on-site inspection.