The Flea Life Cycle

PetMD Editorial
Updated: May 04, 2021
Published: March 11, 2015
Share this:

The flea life cycle may be short, but the impact of fleas can be very upsetting for dogs, cats and their owners. Once an adult flea lands on a dog or cat, they begin to bite and feed on the dog or cat’s blood.

These flea bites can be very irritating for dogs and cats and can cause intense itching. After two days, once the female adult fleas have a “blood meal,” they will begin laying eggs—and they can lay up to 40 eggs every day.

The flea eggs drop off your pet and are scattered around your home in places where your pet spends their time. They can take anywhere between two days to two weeks to hatch.

Once the flea eggs begin hatching, they eat the flea dirt left behind by the adult fleas, and will begin to build cocoons in about 5-20 days to transition into the pupae stage. They will remain within the cocoons for several days to a few weeks—and sometimes up to several months or years—before emerging as adult fleas and restarting the flea life cycle.

To help protect your pet from a flea infestation, it is important to find prescription flea and tick prevention. The flea and tick medicine for dogs or the flea medicine for cats that you choose should include ingredients that not only kill the adult fleas when they bite your pet, but also stop the development of flea eggs into the larvae and pupae stages.