Understanding the Life Cycle of a Flea

ctenocephalides canis dog fleaKnowing how the flea life cycle works can be a crucial weapon in the fight against flea infestations and effectively using flea treatments.

The typical flea life can take just fourteen days, which makes for a continuous infestation if your pet and home are not successfully treated.

There are three previous stages before adult fleas become fully developed.


1) Eggs

In the first stage of the flea life cycle, the female lays eggs after feeding on their host. These eggs are small and white, and are marginally smaller than a grain of sand in size. They are laid in your pet’s fur, typically in batches of around 20 at a time. As the typical female flea can lay up to 50 eggs per day, the number of eggs in your pet’s fur can quickly multiply.

Because flea eggs are not sticky, they will fall out of your pet’s fur onto carpets, furniture and other areas during day-to-day movement around the home. This enables the eggs to develop within the home itself – as well as on your pet – and is an important reason why you should treat your entire home when tackling flea infestations. Once eggs have transferred into your pet’s environment, only treating your pet will not be effective in eradicating a flea infestation.

Hatching can take anything from a couple of days to weeks depending on whether conditions are ripe for this. In cold, dry temperatures, flea eggs will take longer to develop compared to warmer and more humid conditions.

 2) Larvae

The second stage of the flea life cycle comes once the eggs have hatched. They then develop in larvae, which feast on pre-digested blood (known as “flea dirt”) from adult fleas and organic material in the environment. Flea larvae can be up to a quarter of an inch in length and have a relatively see-through appearance. When conditions are favourable, larvae will move onto the pupae stage.

 3) Pupae

This is the last stage before becoming a fully-fledged adult flea. Pupae are protected by a cocoon for days, weeks or even years before adult fleas emerge. Various stimuli can encourage an emergence from the cocoon including warm conditions, humidity, carbon dioxide emissions from your pet passing by and even vibrations. These stimuli suggest the presence of a host, which can then be jumped onto once the adult fleas leave the cocoon. The stickiness of the cocoon allows deep penetration into carpets and furniture, which vacuuming and dusting will not easily dislodge.

4) Adult Fleas

Once adult fleas emerge from their protective cocoon, they will begin to feed on their host. Female fleas generally live for several weeks on their host and in this time frame, they will start laying eggs for a new infestation – and so the cycle continues.

How This Impacts Flea Treatments

Because the flea life cycle goes through various different stages, it isn’t sufficient to just treat your pet with flea treatments. Eggs will inevitably drop off your pet and be transferred onto areas that are frequented by your pet, making it vitally important that you also treat these areas to prevent further development into fleas.

[Photo Credit: Luis Fernández García]