Fleas: Tiny Pests, Big Problems

Facts About Fleas

The world is host to over 2,000 species of fleas, and the most common flea is ctenocephalides felis, the "cat flea." Despite its name, the cat flea affects dogs and cats, wild animals like raccoons and skunks, and pet owners.

Quick flea facts:

  • A flea can jump more than 100 times its length.
  • Fleas will start feeding on your pet within 5 minutes, and can live there for almost two months.
  • They can lay eggs at a rate of 40-50 eggs per day through their life.
  • Larvae can burrow into fabrics, bedding and carpeting for weeks to months, emerging and infesting on your pet when conditions are optimum.
  • Fleas can transmit tapeworm and bacterial diseases to dogs, cats and even humans.

Flea Growth Chart

Slide from left to right to see how quickly fleas can lay eggs and reproduce.

Flea Eggs: 816

Most dogs and cats will pick up fleas at least once in their lifetime—even pets that never go outdoors are at risk.

Getting fleas doesn’t have to be a big deal if you catch and stop fleas early. Routinely checking for fleas, and always keeping an eye out, can help prevent major infestations.

  • Part the coat near the base of the tail with your hands or a flea comb. Fleas are about the size of a pinhead and may move when disturbed.
  • If you don’t see fleas, check for dark, pepper-like particles on the skin or coat. These may be signs of flea droppings (known as flea dirt).
  • If you're unsure if it’s flea dirt, dab it with a wet paper towel or cotton ball. If you see dark reddish brown or orange swirls it is flea dirt and your pet has fleas.

If you find fleas, take action right away by contacting your veterinarian!

Breaking the Flea Life Cycle

Did you know that for every flea on your pet, there are about nine more in your home? You might think you’ve accomplished getting rid of fleas, only to find a new generation emerging days to weeks later.

To avoid this, veterinarians recommend using monthly topical flea products all year round, for every pet in your home. This kills adult fleas and newly hatched fleas to break the flea cycle and stop re-infestations.

In addition to treatment, it’s best to clean your house thoroughly the same day. Be sure to wash pet bedding at a high temperature and vacuum all carpets and furniture (discarding vacuum bag after use).


  • Starts feeding within five minutes.
  • Females can ingest 15-times their body weight in blood.
  • Mate four-to-48 hours after feeding.
  • Prefer to stay on host animal for life.


  • Large numbers of eggs (e.g. 40-to-50) laid every day.
  • Fall off pet onto floor and furnishings.
  • Hatch as larvae in as little as one to 10 days.
  • 25-to-30% develop into adult fleas.


  • Thrive in warm, humid conditions. Hide deep in rugs, furnishings and between floorboards.
  • Feed on adult flea droppings and organic material like skin debris from dogs and cats. Weave cocoons.


  • Develop (metamorphose) into adults inside tiny cocoons.
  • Pupae can stay dormant for long periods inside these cocoons.
  • Quite resistant to temperature, drying and insecticides.
  • Emerge in response to heat, CO2 and movement.

The Problematic Parasite

Ticks can carry diseases that affect both pets and their owners.

About Ticks

Stay informed with more resources and tools from MyPet.

Further Reading

Find more information, facts, and treatment options for stopping and preventing fleas and ticks inside and outside your home.

Learn More

MyPet Newsletter

Join the pet parenting newsletter that really delivers. Sign up to receive useful pet parent tips delivered right to your inbox.

Sign Up
  1. Blagburn BL, Dryden MW. Biology, treatment, and control of flea and tick infestations. Vet Clin N Am Small Anim Pract. 2009;39(6):1173-1200.
  2. Dryden M, Rust M. The cat flea: biology, ecology and control. Vet Parasitol. 1994;52:1-19.
  3. Data on file, Merck Animal Health
  4. Guerino F, Qureshi T, Hair J, Young D, Fiourie J. Indoxacarb Kills Developing Stages of Fleas in the Environment of Treated Cats. Presented at the WSAVA/FECAVA/BSAVA World Congress. 12-15 April 2012. Birmingham, UK.
  5. Frontline® is a registered trademark of Merial.
  6. Dryden MW, et al. Parasites & Vectors. 2013;6:366.