Fleas are tiny – only around 2mm in length and their distinguishing characteristic is that their bodies are very narrow. They do not have wings and are dark in colour. They are well adapted to their way of life; their narrow body allows them to move around very quickly among hairs or feathers.

Their back legs are powerful enabling them to jump. We encounter only three species of flea in the UK – the cat flea is by far the most common. Less often, dog fleas are a problem, and although now very rare, the human flea is still a possibility.

Fleas are parasites. They live exclusively on the blood they take from warm-blooded animals – these are the ‘host’. Each species has a preferred host, e.g. cat fleas prefer cats and dog fleas prefer dogs.

However, each species can feed from other animals (and people). Fleas are often found on the host’s bedding as well as carpets and soft furnishings. An infestation of fleas in your home may not come to your attention until a cat or dog is removed from a house or flat.

Left isolated and hungry and now without their preferred host, the fleas left behind have no choice but to move to people. While cat and dog fleas cannot breed without their preferred hosts, they can live for several months on a diet of human blood.

Fleas are capable of carrying and transmitting diseases through their bites. They can also be responsible for parasitic worms such as dog tapeworm. We are fortunate in the UK in that fleas are not generally known to spread disease but the bites – a tiny dark red spot surrounded by a reddened area – along with uncomfortable itching are enough for most people to do something about the problem.

Life Cycle

Flea eggs are only about half a millimetre in length, oval shaped and pearl-white – you will not usually see them with the naked eye. They will be laid in various locations within an infested property including the fur of the cat or dog host or in its bedding.

The eggs hatch in about one week into larvae which feed on a mixture of dead insects, skin particles and the adult flea’s droppings. Flea larvae like to live in dark humid places such as carpets and animal bedding. The larvae then pupate.

After a variable period of time (about three weeks under normal conditions but very much longer in an unoccupied property), adult fleas hatch in response to vibrations made by a passing host. The complete life cycle normally takes four weeks. Once an unoccupied property is reoccupied (typically by a new household with no pet cat) there can be a mass-hatching and an almost immediate re-infestation will result.


Prevention is of course always better than cure. To keep your home flea-free you must keep your pets flea-free. If you are in any doubt about how to achieve this you should seek your vet’s advice.

Regular vacuuming and cleaning of carpets is a good way of removing eggs, larvae and pupa to interrupt the lifecycle and to stop any fleas from breeding in your home.

If you already have an infestation, try to identify the source of the problem. In most cases this can be traced to a present (or often recently absent) family pet. If you suspect the source is a pet you may wish to consult your vet who may confirm your suspicions and recommend appropriate treatment. At the same time as your pet is treated you must also thoroughly clean your floors (vacuum clean all carpets). You must empty the vacuum cleaner afterwards.

To be thorough, bearing in mind the cleaner itself may now contain eggs, larvae, pupae and adult fleas, you should dispose of the contents outdoors and spray the inside the cleaner and any new bag used with a crawling insect spray (available from supermarkets, pharmacies and DIY stores).

In the case of small, recent and localised infestations, you may be able to successfully treat the infested rooms yourself with either a specialist product (available from your vet), or any general purpose crawling insect spray. Follow the manufacturer’s instructions carefully.

If you have a more extensive or persistent infestation you need the help of a professional pest controller. On request, we will treat your home with a professional residual insecticide.

Before treatment we ask you to clean and tidy the rooms to be treated and vacuum the carpets. We normally carry out a single spray treatment of the floors and soft furnishings (if possible).

We then ask you not to clean or vacuum the treated areas. These should remain undisturbed for a minimum of seven days. This ensures the all-important ‘residue’ of the insecticide kills emerging fleas that were in the pupa stage at the time of treatment. The insecticide we use also includes an insect growth regulator that prevents further reproduction by any survivors of this process.

Please refer to the treatment service fees and charges on our pest control homepage.