The Flea Life Cycle and How It Affects Your Pet

Share on

Learn the four stages of the flea life cycle.

Just one flea on your dog or cat can signal a huge problem. In fact, a single flea can lay up to 50 eggs in one day1 . These eggs can then roll off your pet and infest the environment —wherever your pet goes, fleas and their eggs will go, too. Before you even realize you have a problem, just a few fleas can quickly become hundreds that may infest your home and bite your pet.

Since humans can only see adult fleas, it can be difficult to grasp the full scope of an infestation. Most pet owners focus treatment efforts on the adult fleas they see crawling on their pets and are unaware of the younger stages of fleas growing in the surrounding environment. Unfortunately, adult fleas make up only 5% of the total flea infestation problem. The other 95% are invisible to the naked eye.2

Understanding the four stages of the flea life cycle, including how long fleas live, can help you put a stop to a seemingly never-ending invasion.

A Terrier dog scratching its neck from fleas.

The 4 Stages of the Flea Life Cycle

Stage 1: Flea Eggs

One flea can lay up to 50 eggs in one day, which fall off your dog or cat anywhere they go. As your pet moves around, flea eggs disperse into the surroundings, including carpet, bedding and the backyard.

Stage 2: Flea Larvae

Flea larvae hatch from eggs in one to 10 days. Flea larvae feed on organic debris, don’t like sunlight and live in moist, dark areas such as:

  • In carpeting
  • Under furniture
  • Under baseboards
  • In bedding
  • In shaded areas of your yard

Stage 3: Flea Pupae

Larvae turn into pupae by enclosing themselves in a sticky, silk‐like cocoon. They usually emerge as adult fleas one to two weeks later, but can stay in their cocoons for weeks or months waiting for a host — like your dog or cat — to live on.

Stage 4: Flea Adults on Your Dog or Cat

You can see fully grown fleas with the naked eye, and they begin biting almost immediately after getting onto your pet. Contrary to popular belief, fleas neither jump from pet to pet nor fly because they do not have wings. They stay on one pet biting, feeding and laying eggs for up to several months.

If a flea cannot find a dog or cat to jump on, it’s not uncommon for them to jump on and bite people. This is why some people experience flea infestations and flea bites after returning from vacation or moving into a new house.

How to Prevent and Treat Fleas on Your Pet

Killing fleas across various life stages helps break the flea life cycle and prevent fleas from biting your cat or dog. That’s why it’s important to use a product that both treats and prevents fleas.

These products work in two ways:

  1. They kill the adult fleas on your cat or dog.
  2. They break the flea life cycle by killing flea larvae, an immature stage of a flea.

When it comes to flea prevention for your pet, there are many products available from your veterinarian or local pet store. You can also prevent fleas with routine, year-round use of a flea preventive that kills fleas through contact.

1. Dryden MW. Host association, on-host longevity and egg production of Ctenocephalides felis felis. Vet Parasitol. 1989;34:117-22

2. Grace SF. Fleas. In: Norsworthy GD, Crystal MA, Grace SF, et al, eds. (2006). The Feline Patient. 3rd ed. Ames, IA: Blackwell Publishing; 106-107.

Share On