What Do Fleas Look Like on Cats?

Updated Aug. 15, 2023
cat getting combed

Even though fleas are a risk to your cat year-round, they are most active during the warmer months, starting as early as March. Many people believe that their cats are safe from fleas after the first frost, but unfortunately, this is not the case.

There are more than 200 types of fleas that can be found on animals in the United States. The use of a flea prevention year-round is the best strategy for keeping your cat and your home flea-free.

How to Tell If Your Cat Has Fleas

Fleas are very active insects. They can jump onto passing animals and burrow down into the fur to the skin, where they stay hidden while biting and ingesting blood. This is irritating to the cat, as the bites can cause severe itching, allergic reactions, and inflammation.

Fleas are small, wingless, flat insects with three pairs of legs. The adult flea is only about 1/8 of an inch long (1-3 mm) and looks like a small black fleck. Fleas can be seen in cats as live insects or small brown-black flecks that look like dirt. These tiny flecks are flea dirt, which is the feces from the flea.

It’s important to remember that even indoor cats get fleas. Once fleas get into your home, they multiply rapidly. The most common way for fleas to enter your household is on the family dog or another pet that comes inside after being outdoors. Cats can also get fleas from neighbor pets, new environments, and other local wildlife such as birds, rabbits, raccoons, opossums, squirrels, and skunks.

Symptoms of Fleas on Cats

The fleas most likely on your cat are newly hatched adult fleas that come from your house or yard, where they wait until your pet is nearby. The tiny flea jumps onto your cat and finds a warm, moist, safe environment in your cat’s furry coat. If your cat starts to scratch and bite at skin and fur, that is highly suggestive of a flea problem.

Another sign that cats might have fleas is restlessness and behaving abnormally, as fleas are very irritating to a cat. Shaking the head and scratching at the ears is another indication that your cat might have a flea problem, as fleas like to hide in those areas. Overgrooming is another thing to watch for, as excessive licking and hair loss can be signs of itchy skin. Most often, cats will have few or no symptoms, so it is important to have your cat checked routinely when they go to the veterinarian for routine healthy checkups and when they are not feeling well.

How to Check Your Cat for Fleas

If you suspect your cat has fleas, the first place to check is the skin around the base of the tail or under the armpits and in the groin region. Look for tiny, moving black dots.

It’s a good idea to use a flea comb to brush your cat’s fur along the back and legs to see if you can catch the fleas in this narrow-toothed device. The comb’s teeth are designed to catch and pull fleas out from under the hair coat. While you are combing your cat, get down to the skin with the comb, then empty the contents of the comb into a bowl of soapy water. Getting the live fleas into the water quickly will kill them; otherwise, they might jump off the comb and back into your home.

Since fleas take a blood meal from your cat when they attach, a special trick can determine if the black fleck you found on your cat is a flea. While using the flea comb, keep a white paper towel under you cat. Flea “dirt,” actually flea feces, will fall off the cat’s skin and land on the towel. Add a very small amount of water to the towel, and if those black flecks turn dark reddish-brown in color, you know you have a flea issue. What you are seeing is the digested blood that the flea passed in its feces.

What Do Fleas on Cats Look Like?

Flea eggs are nearly microscopic. They are about 0.5 mm in length and about half as wide, which is about the size of a grain of salt. People often mistake flea dirt for flea eggs, though both are signs of a flea infestation. Unlike flea eggs, flea dirt is dark and crumbly. Flea dirt itself is not harmful to your cat and can be easily washed away with a bath, but it is almost always an indication of a bigger flea problem.

Since flea eggs are easily mistaken for dry skin or sand, they’re usually not the first thing you notice if you think your cat has a flea problem. Finding flea dirt or actual fleas on your pet or in the home are more obvious signs of a flea infestation.

Adult fleas themselves are noticeable as very fast-moving tiny black insects. At this stage, they do not stay on your cat exclusively and can move throughout your home, especially in areas where your cat spends a lot of time.

Can Cats Die from a Flea Infestation?

Fleas are always a huge nuisance, but they can also be deadly if not treated in a timely manner. The most significant side effect of a severe flea infestation in cats is anemia. While flea anemia can affect cats of all ages, kittens are at a higher risk for the most severe side effects.

Kittens do not always have the classic itchy skin with a flea problem. Because their bodies are so small, they are susceptible to anemia due to loss of blood from fleas feeding on them.

Signs of anemia in kittens include:

  • Pale gums

  • Lethargy

  • Weakness

  • Decreased appetite

  • Collapse

If you suspect your kitten has fleas, it’s important to get to the vet for a full physical examination as soon as possible. 

What Do Fleas Look Like on Cats FAQs

How can you tell if a cat has fleas?

The first place to check is the skin around the base of the tail or under the armpits and in the groin region. Look for tiny moving black dots and use a flea comb to help you pull out the fleas to confirm.

What is the fastest way to get rid of fleas on a cat?

The fastest way to kill fleas on a cat would be giving your cat a bath with warm water and Dawn dish soap. As most cats are not easy to bathe, another option is to kill adult fleas with nitenpyram (Capstar), an oral medication. This pill starts to kill live adult fleas in 30 minutes. It’s always best to use this with a topical flea prevention to make sure fleas in other life stages are killed, as well as removing flea dirt by combing them. It is best to use a combination of flea products, as Capstar only kills live, adult fleas (it does not get rid of flea eggs or larvae).

Can an indoor cat get fleas?

Indoor cats are just as susceptible to fleas as any other cat. Fleas use their strong back legs to jump onto pets—and humans—as they walk by. Fleas also multiply rapidly; when feeding on a host animal, a single flea can lay up to 50 eggs a day. Unfortunately, this can happen inside your home, not just outdoors. Indoor cats can get fleas in more ways than you might think.

Can humans get fleas from cats?

While fleas do not live and reproduce on people, they can still jump from the environment or your cat onto you. Fleas will bite the lower legs, ankles, and feet of people and cause a mild itch and red skin lesions.

Featured Image: iStock.com/Rich Legg

Barri J. Morrison, DVM


Barri J. Morrison, DVM


Barri Morrison was born and raised and currently resides in Ft. Lauderdale, Florida. She went to University of Florida for her...

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