Historically, fleas tended to be active when our British weather warmed up in the spring and summer seasons.

The most common species of flea in the UK is the Cat flea Ctenocephalides felis.

They are an extremely common pest whose primary host is domestic cats, but are known for readily biting humans and dogs too.

Fleas are a type of external parasite. There are different species of fleas, such as dog fleas, cat fleas, rabbit fleas and human fleas. It's possible for many species of fleas can infest more than one host species. 

Fleas only suck blood from their hosts as adults. Adult fleas have mouthparts that are adapted for piercing skin and sucking blood from their host.

  • A flea can live from between 14 days to a year, and a female can lay up to 50 eggs in one day - that's 1,500 in a lifetime!
  • Some types of flea can leap more than a hundred times their own body length.
  • It's estimated that 95 per cent of flea eggs, larvae and pupae live in the environment, not on your pet.

The following is according to Frontline.

What a home infestation really means

To understand how these signs of a home infestation have come about and how to solve the problem, we need to know how the flea life cycle works. There are two key points:

1. Each female flea on a pet can lay up to 50 eggs a day. These fall off the pets around the home.

2. The fleas we see on our pets are just 5% of the total flea population in an infestation. That’s because 95% are in the pet’s environment (our homes!) as in other flea life stages.

Recommended reading:

Vet's flea warning to all dog and cat owners in the UK

Family moved out of home after infestation by fleas

Pet owners are facing an 'imminent' flea invasion

The flea life cycle

Adult fleas jump on our pets and feed and breed while on them. 

The flea eggs that adult fleas lay fall off our pets wherever they go, and develop into flea larvae.

Flea larvae burrow into carpets, furnishings and cracks, away from the light, and spin cocoons to become flea pupae.

Flea pupae contain developing, immature fleas. When they’re fully grown and detect warmth, vibrations and carbon dioxide from an animal (or from us),  these new fleas hatch out and the life cycle starts all over again.

How to solve a home infestation

Because of the way the flea life cycle works, there are a few things to do to get on top of an infestation. We’ve got all the advice you need in our five-step guide covering how to get rid of fleas in the house.

If you’ve not seen signs of an infestation yet, it’s worth bearing in mind that fleas can be hard to spot until an infestation becomes quite severe. The easiest way to avoid the problem is to treat pets regularly. Take a look at our three-step guide to flea prevention for cats and dogs.

Flea infestations can seem daunting, but with the right actions and some patience, we’ll start to win against the fleas. And then we’ll get our homes (and pets) back to how we want them – minus these irritating insects.

Tiny white things on the floor or pet bedding

Flea eggs and larvae are pretty small and so are hard to spot. If there’s a home infestation, we might see things that look like grains of sand or salt, little white caterpillars on the floor or other places our pets go, such as their bed or a sofa. 

The things that look like little grains of sand will be flea eggs. They’re white, oval and only about half a millimetre long, so it’s easy to mistake them for a bit of dry skin or something less harmful than a flea egg.

The white caterpillar-looking things will be flea larvae. Flea eggs hatch into flea larvae that burrow into carpets, furnishings and nooks and crannies – such as skirting boards and between floorboards – so you might not even see them at all. They’re about 2-5 mm long.

Scratching pets

If pets are scratching, overgrooming or have bits of flea dirt on them (this looks like normal dirt but goes reddish brown when on damp paper) these are signs they have an infestation, and a pet infestation inevitably leads to a home infestation.