What do Fleas Look Like? – Pictures of Fleas

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What do Fleas Look Like?
What do Fleas Look Like?

Although fleas are tiny parasites, they can make your pet itchy and uncomfortable and stress them out. These small creatures appear as reddish-brown or brown, and they suck blood from their host.

You can spot adult fleas on your dogs if you are keen, but they are known to hide in the fur. Fleas are also capable jumpers, and they can jump for up to 30 cm to latch onto pets and humans.

If you’re wondering what fleas look like, here are some pictures to help you figure out if you’ve got them.


Pictures of Fleas

Male Flea
Male Flea (sourceCC BY-SA 4.0)
Female Flea
Female Flea (sourceCC BY-SA 4.0)
Flea under Microscope
Flea under Microscope
Human Flea - Male & Female
Human Flea – Male & Female
Dog Flea
Dog Flea

Different Types of Fleas

There are over 2,000 flea varieties across the world which target warm-blooded animals, including humans. The different types of fleas include:

Cat Fleas

The cat flea (Ctenocephalides felis) has populations across the globe, but it is mostly found in North America. Despite its primary host being the domesticated cat, cat fleas are also found on dogs, guinea pigs, rabbits, and on other omnivores and carnivores. The parasites are the most common types of fleas found inside households.

The cat flea is extremely thin, which makes it hard to spot even if your pet’s coat is white. If your pet is infested with a lot of them, they can lose sufficient bodily fluid to become dehydrated or suffer from anemia. With female cat fleas laying up to one egg every hour, it is quite natural for the parasites to cause a severe infestation.

Dog Fleas

The dog flea (Ctenocephalides canis) mainly targets dogs and cats, but it can make a host out of a variety of mammals. While it closely resembles the cat flea, it is more prevalent worldwide, and it can live in a broader range of hosts. Dog fleas are mainly found in Europe, although populations reside in the US as well.

Female dog fleas can lay hundreds of eggs throughout her life, with the lifecycles from egg to adult taking two to three weeks. The parasite can spread Dipylidium caninum in addition to causing anemia and transmitting tapeworms and other diseases.

Human Fleas

The human flea (Pulex irritans) is thought to have its origins in South America from the guinea pig or peccary. The most common hosts of the flea include humans, pigs, and rats. Human fleas are also more common in North America in comparison to dog fleas.

Human fleas are known for being capable of spreading the plague by carrying the disease’s bacterium. The plague was especially deadly in the Middle Ages, but it is currently treatable with modern antibiotics.

Oriental Rat Flea

The oriental rat flea (Xenopsylla cheopsis) can live on any warm-blooded mammal, although its primary hosts are rodents. Unlike most of the other fleas, the oriental rat flea lacks genal or pronotal combs. Its body is adapted to jumping long distances, and it measures about 2.5 mm.

The oriental rat flea was first collected by Charles Rothchild and Karl Jordan in Egypt, and it was described in 1903. It is a primary vector for murine typhus and bubonic plague, and it also hosts several species of tapeworm.

What Does a Flea Bite Look Like?

Fleas cause tiny, red, and raised dots on the skin. The bites are often smaller than those of other insect bites, but they can become inflamed if your pet scratches the bitten area. You can also see a red ‘halo’ close to the bitten center. Flea bites typically occur in clusters of three to four or in a straight line.

Flea bites are easier to detect on human skin due to the lack of fur. Pet owners will be more successful in finding evidence of fleas rather than flea bites.

To determine if your pet has been infested with fleas, start by looking for flea dirt. Since fleas rely on the blood of hosts for survival, their feces contain digested blood. Run a fine-toothed flea comb through the fur of your dog to pick pieces of flea dirt or even adult fleas.

You can place the dirt on a damp paper towel to determine if it indeed flea feces or usual dirt. The former will reveal a red color, and you can assume that your pet has fleas.

You should also rule out any other insect bites to avoid treating your dog for the wrong concern. Most bug bites leave a similar center of localized redness. When compared to mosquito bites, flea bites can appear at any time, and they take a shorter time to resolve. Tick bites, on the other hand, will mostly develop a raised sore or a scab.

Once you are sure that your pet has been bitten by fleas, you should determine the severity of the infestation. Get your dog in a comfortable position with their belly exposed. Evaluate areas like the inside of thighs, armpits, around the tail, and under the neck and chin. You can subsequently soothe your pet with a warm bath.

What do Flea Eggs Look Like?

Flea eggs are as tiny as a grain of salt, which makes it hard to detect them. They are oval in shape and have an off-white hue. It is quite easy to mistake a flea egg for a speck of dirt.

Flea eggs are typically produced when a female flea has a blood meal, that is when it feeds on the blood of the host. Since an adult female can lay up to 40 eggs in one day, flea infestations can become severe quickly. If conditions are good, the eggs will hatch in two weeks.

Flea eggs make up around 50% of the adult population in an infestation. It is important to kill the eggs when dealing with an infestation through means like bathing your dog in a flea-killing shampoo.

Do Fleas Have Wings?

Like other ectoparasites of mammals, including lice and ticks, fleas are wingless. Fleas are, however, well adapted to jumping, which makes it easy for them to find hosts.

How do Fleas Get into Your Home?

Fleas are common in homes with pets like dogs and cats. These household pets can pick up the parasites from the outdoors or through contact with infested animals.

If you run a pet-less residence, fleas can be living on rodents in the ceiling or attic. Fleas are extremely resilient, and they can crawl through walls, light fixtures, and ceiling gaps. The parasites can also get into your home if a guest whose clothes have them visit or through old furniture.

If you move into a house where previous owners kept dogs and/or cats, there can be fleas already present. Flea pupae can enter a cocoon stage during their growth into adulthood. They will remain in this protected state for a significant period. To determine if a new host has arrived, the pupae mostly detect warmth and movement.

Once you suspect the presence of fleas in your house, it is time for a comprehensive inspection. Check your pet’s bedding and living area for live fleas as well as flea dirt. You should also check any upholstered furniture, carpets, and rugs.

Are Fleas Dangerous to Pets and Humans?

Fleas are associated with negative effects not only on pets but also on humans.

The parasites can spread numerous diseases to your dog, including:


Fleas have rapid reproductive rates, which means that several of them on your dog’s coat will quickly turn into hundreds. Since the parasites feed on blood, they will depend on your dog’s supply for survival. The situation is especially severe in puppies with a still-developing immune system.

The red-blood-cell count of a dog infested by fleas decreases as they continue to host the parasites. An anemic dog will exhibit lethargy, weakness, and rapid breathing. Death can ensue in severe cases, which is why it is crucial to address the situation early on.

Flea Allergy Dermatitis

Flea allergy dermatitis is a particular allergy to flea saliva. A dog with this allergy will itch and scratch, which will cause broken areas of skin that can get infected. Although the itchiness can occur at any part of the body, the most common area is at the base and back of the tail.

The resulting skin infections and hair loss will further aggravate the problem. This condition needs veterinary consultation, where the fleas will be removed, and allergy medication will be given.


While this concern was previously only associated with cats, there is evidence that dogs can also be infected with Bartonella bacteria. The symptoms include diarrhea, vomiting irregular heartbeat, loss of appetite, fever, and nausea.


Dogs will commonly chew at irritated skin in a bid to get relief. It is also possible for them to swallow the parasites when they lick their legs to get rid of dirt. If the ingested fleas happen to have tapeworms, your pet will subsequently get them.

Tapeworms are known to latch onto the intestinal lining and cause symptoms like vomiting. You can easily spot pieces of tapeworms dangling from the anus of your pet.

Fleabites on humans are painful and sore. You can notice a rash or hives near the location of the bite. If the bitten area becomes infected, a person can experience swollen glands or excessive redness. The bites can also trigger an allergic reaction.

Although fleas, in general, do not carry diseases, they have been known to spread typhus, plague, and cat scratch fever.


Fleas are quite small, and this characteristic makes them quite hard to spot and deal with. There are endless varieties of the parasite which target warm-blooded animals.

If you detect a flea infestation on your dog, you should address it as soon as possible since they reproduce quickly and can cause anemia in your pet.

Updated: December 27, 2019

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