What Do Baby Fleas Look Like?

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Fleas are a major concern for pet owners, but spotting them can be challenging. Before using flea remedies, it's good to know what you are looking for and why. No dog or cat wants to be a flea baby (or adult) host.

The flea life cycle has four distinct phases.
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What a flea baby looks like depends on which of three pre-adult life stages you call the "baby" stage. The flea life cycle has four distinct phases — the egg stage, the larval stage, the pupal stage, and adulthood. Fleas are parasitic bloodsuckers only in their adult stage. In their other stages, they're generally found not on hosts but in the hosts' bedding and other favorite lounging spots. There are many ways to get rid of fleas at each development stage.


Stage one: flea eggs

Adult female fleas lay an average of 20 to 30 eggs a day. Flea eggs are not sticky; they are dry and smooth. They tend to slide off the hair of host animals — so they're usually found scattered in your pet's bedding. Flea eggs are extremely tiny, typically measuring 0.05 millimeter (.002 inches) in length. You will have a difficult time seeing them with your naked eye, though, because they are almost microscopic. Eggs look like oval-shaped grains of salt.


Stage two: flea baby larvae

Within 12 days of being laid, flea larvae emerge from eggs. Flea larvae are between 3 and 5.2 millimeters (.12 and .2 inches) long. Flea larvae are wormlike, white, and semi-transparent, but they darken as they grow because they feed primarily on adult flea feces. Fleas will stay in the larval stage between 4 and 18 days. During this time, they have three molts, also called instars. During the third instar, they begin to create cocoons.


Stage three: flea pupal

Flea larvae make their cocoons by secreting a silky substance and binding it to materials in their environment.
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Flea larvae make their cocoons by secreting a silky substance and binding it to materials in their environment, helping them to camouflage themselves. Their coverings are lumpy, crusty, and irregularly shaped. The pupal stage can last between three days to one year, because pupae do not emerge from these cocoons until they know a host is near, sensing them from vibrations or carbon dioxide. Once they are on your cat and dog, there are a few ways to kill them naturally, but first you need to identify adults.


Adults, feeding, and flea dirt

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Fleas emerge from the pupal stage as adults. They seek hosts and begin feeding on their hosts' blood. They can survive in bedding and carpeting as long as host animals are available to feed on. Fleas can feed on people, but prefer furry animals if they're available. This includes any furry pet: cat, dog, rabbit, rat, and mice. Fleas can travel from pet to pet.


Living fleas on dogs, or any pet, shed reddish-black waste that could wind up on your pet's bedding — don't mistake this feces, or flea dirt, for pupae, eggs, or larvae. Smear a fleck of it on white paper — does it turn reddish or rusty? If yes, your dog has fleas.