Spotting the signs of a home flea infestation

Flea eggs and larvae are pretty small and so are hard to spot. If there’s a home infestation, we might just see things that look like grains of sand or salt, or 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.

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. You can find out more about these signs in our how to spot fleas on your pet quick guide.

To understand how these signs of a home infestation have come about and how to solve the problem, we need to know a bit about 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 pet 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 other flea life stages.

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.

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 flea-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.