Flea Life Cycle & Lifespan Stages: 7 Facts

The flea life cycle consists of four stages: egg, flea larva, pupa, and the adult. Fleas will live from a few weeks to several months given optimal humidity and temperature (70 percent and 70–85°F).

  • Fleas feed on blood, and the cycle of a flea’s life is closely aligned with that need.
  • Flea eggs hatch into larvae, which then turn into pupae before emerging as adults. The adults lay eggs as they feed to continue the cycle.

Understanding the flea life cycle functions can help you better protect your pet and home from these parasites!

In this article, we’ll take a look at the cycle of their life. Also, check this fleas movement guide.

Understanding the Flea Life Cycle – 7 Facts

1. Flea Eggs

The life cycle for a flea typically starts when an adult female will lay their eggs after feeding on blood from a suitable the host, this is mainly cats or dogs.

One half (50%) of the average home’s flea population are flea eggs. Without blood, adult fleas cannot reproduce.

  • A female flea can lay up to 40 eggs per day and as many as 2000 in her lifetime!
  • The eggs are sticky, so they will stick to the fur of your pet. This is called “biting” or “bloodsucking”.

On size, flea eggs are about 0.12mm long and they are yellowish-white in color and they’ll be laid in batches of 20 eggs on the pet’s fur.

A female will lay from one to two batches, or 50% of its total offspring’s eggs at a time, on your pet’s fur before moving on to a new host.

Flea eggs fall from your pet as they move, distributing them in the yard or house.

Related: Flea spray for yard

Flea eggs hatch with the right temperature and humidity with 2-14 days. Larvae will emerge if temperatures are warm and humidity levels are high.

2. Flea Larvae

Flea eggs can remain dormant for up to 18 months until they sense enough heat, which triggers an egg to hatch ( into larvae) within seconds!

Flea larvae constitute about 35-percent of fleas in your house. The newly hatched larvae will start looking for food immediately.

  • The larvae will feed on organic debris on the floor or your pet’s fur and hair until they pupate, transforming into an adult flea within a few days.

Flea larvae emerge being wormlike and when – while also hiding from light. Larvae will eat flea dirt (pre-digested blood) and various organic debris they get in their surrounding.

After feeding, the flea larvae will spin themselves into a cocoon and pupate (transform from an insect-like larva to adult). During this stage they are highly vulnerable if disturbed or exposed to light.

The whole process can take just two weeks with very warm temperatures and humidity levels, or more than a year with cold temperatures.

On size, flea larvae measure around a few millimeters (¼-inch) long, they’ll look transparent (somehow white) and have a slightly bent tail.

Flea larvae will be the first thing you’ll spot on your pet’s fur or skin, and they might look like tiny white worms that wriggle around.

3. Flea Pupae

Flea pupae will constitute roughly 10-percent of the fleas in your home. They will be dark brown in color and look like a “J” shape.

Flea pupae are hard to spot because they’re not moving much, but they don’t flee from light either – which makes them easier targets for you.

They’ll make your inspection process easy when it’s time to take care of fleas once-and-for-all; on color they’re white to yellow and to brown.

This is the last stage on flea development before you get adult fleas. Its cocoon safeguards the pupae for up to weeks or months depending on the environmental conditions.

The sticky outer coating on the cocoon allows it to protect and hide the flea larvae deep inside rugs and carpeting.

  • Can you see flea pupae? Yes, if eggs or larvae can be seen, you will probably also see flea pupae. Though its appearance may seem like debris at first, flea pupae are really just a phase in the lifecycle of this fleas.
  • What kills flea pupae? The only way to kill flea pupae is by treating your home with a household “flea” treatment. To encourage them to hatch, vacuum the house first. Once they have hatched into adult “fleas,” they will be killed by the insecticide in your flea treatment.
  • What triggers make flea pupae hatch? The timing of when a flea will emerge is triggered by vibrations, high carbon dioxide, and heat – these are signs of presence of a host (warm-blooded). Vacuuming can trigger the flea pupae to hatch.

Therefore, flea pupae will only hatch out of their cocoons and into a “flea” life stage if they sense vibrations, high carbon dioxide, and heat brought by a pet or human being.

Related: Puppy Shampoo for Fleas

4. Adult Fleas

After emerging from their cocoon, adult fleas start feeding (sucking blood) within 1-3 hours and becomes ready to breed and lay eggs in a few days.

Adult fleas constitute about 5-percent of the flea population in your home. Female fleas cannot lay eggs until they have had a blood meal.

On appearance, fleas are black (flat-bodied) and can be seen with the naked eye. Fleas begin life very small but will bulge upon feeding on host’s blood.

Female fleas have a tube-like mouth structure, called a rostrum, which they use to pierce the skin of their host as well as suck blood from them. The saliva that is injected during this process contains an anticoagulant so it’s easier for the flea to feed.

The saliva also contains a substance that prevents blood from clotting until they are done feeding which can take several minutes or hours depending on how much time each individual spends between meals.

Fleas do not have teeth to chew food so when their stomachs fill up, they release digestive juices into the host’s blood which breaks down the host’s cells. This is what gives a flea its red coloration after it has been feeding for some time on one animal or person.

After this process of digestion, the fleas poop out feces and can leave behind droppings in places where they have lived such as bedding, carpets, blankets and furniture.

Adult fleas will live for several weeks up to months on their host such as a dog or cat or also hiding on carpet edges, cracks, and pet bedding where they get adequate skin and hair.

How to Break the Flea Life Cycle

Fleas take 1 to 2 months before they can develop into an adult flea and be capable of reproducing. As long as flea prevention and control methods are implemented, no new adults will form.

To break the flea life cycle;

  • Use a flea treatment on your pet and clean the house.
  • Wash all your pet’s bedding and
  • Vacuum carpets to remove eggs, larvae, and pupae.

To ensure a flea free environment vacuum carpets, furniture and floors for three weeks. Machine wash toys, bedding and cloth in hot water to kill all flea stages.

You can help speed up the hatching of any remaining flea pupae by increasing the temperature and using a humidifier.

How to Flea Treat My Cats and Dogs

Pets should be treated with a flea treatment including dog flea shampoo or an appropriate cat flea shampoo. Fleas can become resistant to certain treatments, so it is important you use the correct one for your pet’s needs.

A topical or oral medication that has an insect growth regulator (IGR) will help break the life cycle of adult fleas and prevent new from developing into an egg laying female for at least six months.

  • It is important that you use pet shampoos with insecticides, as well as other products such, sprays or lotions on the animal’s coat.
  • Products containing permethrin or pyrethrins are also effective in killing fleas and preventing a new generation from hatching eggs.

It is important that you treat your pets at least twice during the summer months with an IGR product to ensure complete protection, especially if they spend time outside.


In summary, the life cycle of the flea is all about eggs, larvae and pupae.

The adult female lays her fertilized eggs on your pet’s fur for them to hatch into larva or even pupae which then turn into adults after a couple weeks time.

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