The (Not-So) Big, The Bad, & The Flea

The (Not-So) Big, The Bad, & The Flea

For something so small — just 1/12 to 1/8 inches long — fleas are a mighty big problem. One flea can bite up to 400 times per day in a lifespan that can last about 100 days! And one pair of fleas can produce 400 to 500 offspring during that lifetime. In fact, it only takes 21 days for a single flea to multiply into 1,000 fleas on your dog, cat, and home. And those are just adult fleas. YIKES!

Educating yourself about fleas and the problems they cause is the first step to protecting your pet, home, and family.


It's not just the adults that can cause problems. They only make up 5% of an infestation. That means there are eggs, larvae, and immature fleas ready to do their part in keeping an infestation going, making them a menace to pets and their owners.

Stage 1: The Eggs. An adult female flea can lay up to 50 eggs per day and several hundred eggs in a lifetime. While their eggs are tiny, they are not sticky, so they quickly fall off your pet and into your carpet, furniture, bed, and yard. From 2 to 21 days, the eggs are ready to hatch, and then the real problem begins.

Stage 2: The Larvae. Wherever the eggs lay, they hatch into larvae, typically in dark places in and around your home. Hiding discretely in the shadows, the fleas feast on flea dirt — flea feces that contain digested blood from your pet — and other organic matter like shed skin cells, hair, and feathers. To the naked eye, larvae are almost invisible, which allows them to settle deep into carpets and furniture, to the point where even vacuuming won't remove them all.

Stage 3: The Immature Flea. Immature fleas, or pupae, spend about eight to nine days growing and waiting to emerge in their cocoon. Still, they can survive several months if the conditions are right. These fleas stay until they detect heat, movement, and carbon dioxide, letting them know it is time to emerge from their cocoon. If conditions are favorable, they can survive up to a year. They emerge from their cocoon when they detect heat, movement, and carbon dioxide.  

Stage 4: The Adult Flea. Adult fleas like warm, humid places and stay on the same host pet their entire lives. How nice. While they may be the most mature in this stage, they are the most annoying. That’s because adult fleas bite, feeding on your pet's blood. When they do, it results in the telltale symptoms of scratching, biting, and skin irritation. As they feed, female fleas lay eggs, and the life cycle begins all over again.

There are thousands of species of fleas in the world — each with its own preferences regarding the environment, host animal, and other characteristics.

  • Flea varieties.There are more than 2,000 varieties of fleas in the world and more than 200 types in the U.S.

  • Classifying fleas.While each type of flea has different characteristics, they are usually classified by the animal they prefer to call host — dog fleas, cat fleas, and so on. However, fleas don't limit their appetite to their namesake animals.

  • Common U.S. fleas.The most common flea in the U.S. is the cat flea. But don't let the name fool you; it's also the type of flea most found on dogs. Confusing, right?! So, if you have these biting bad boys around, you're probably fighting against the cat flea.


While fleas are no one's favorite, there are many facts to know about this itchy, scratchy foe.

  • Size and shape:Measuring at just 1/12 to 1/8 inches and flat, fleas on your dog or cat move quickly and easily between the hairs in their fur. Like most insects, fleas have six legs to help them navigate the furry forest. With longer hind legs, it makes it easy for them to jump about. 
  • Mobility:Fleas do not fly, but they do jump, reaching up to eight inches high and 12 inches horizontally. So it's easy for fleas to get on dogs and cats…and even pants, shoes, and blankets.

  • Food:Fleas love to feast on the blood of their hosts, including cats, dogs, and other domesticated animals. Female adult fleas ingest 15 times their body weight each day. The immature flea, or pupae, doesn't eat blood but does survive on organic matter like flea feces, and shed skin, hair, and feathers. However, the adult flea must have a blood meal to lay eggs, so you best believe when they have the chance, they are feasting.

  • Infestations:Fleas can live for about 100 days, but only about a week of this is spent as an adult. In fact, 95 percent of a flea's life is spent in its other life stages — from egg to larvae, then pupae or immature flea. That's why an infestation can last much longer than 100 days, as fleas may exist in different stages.
Bites: According to experts, more than 70 percent of fleas bite their host within the first hour. One flea can bite up to 400 times per day. So, getting flea treatment on dogs and cats needs to be fast and effective!
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