Flea Life Cycle

There are four phases in the flea life cycle: egg, larva, pupa and imago (adult). Adult females first feed on blood from the host (required for reproduction) and then lay eggs on the host. These eggs usually fall from the host to the ground and hatch two days to two weeks later. Flea larvae appear and feed off dead insects, blood, or any other organic material. Fleas are usually found in dark places, as the larvae are blind and avoid light. This is why your pet’s bedding, baseboards and dark places (such as under rugs, furniture and carpets) are usually infested with the highest concentration of fleas in different stages of the life cycle. Larvae then pupate and form cocoons one to two weeks later, and adult fleas appear one to two weeks after that. Vibration, heat and carbon dioxide are all signals that adult fleas use to infer that a host is present, at which time they will jump onto the host in search of blood. Adults must eat their first meal within about a week, but can survive two to three years after that between meals – yuck! This is why it is so important to treat your pet and your house (both inside and outside) as soon as you detect a flea problem.

The flea life cycle consists of egg, larva, pupa, and adult stages. This entire cycle can take place in as little as 10 days in warm, humid weather, though it can stretch out to several months if conditions are not just right for flea survival. In order to effectively combat fleas on your pet or in your home, it helps to have an understanding of each stage of their life cycle.

• Egg – at any given time, about half (or 50%) of a flea population is eggs. Read more here about flea eggs.
• Larva – the larva is a worm-like stage that eventually develops into a pupa. About 35% of the population is larvae at any given time. You can read more here about flea larvae.
• Pupa – the pupa is the cacoon stage of development, which consists of about 10% of the population. Read more about pupae here.
• Adult – adults typically make up about 5% of fleas in a population. That means for each adult flea you see, there are about 10 eggs. Read more about adult fleas here.

Eggs (50%)	50%
Larvae (35%)	35%
Pupae (10%)	10%
Adult Fleas (5%)	5%