Several types of bugs can live on cats, ranging from extremely common (fleas) to relatively rare (lice). The most frequent culprits are fleas, ticks, ear mites, skin mites, and lice, each occupying a different niche on your cat’s body. Some stay permanently, others latch on for a meal and leave, and a few can even bite you too.
Fleas: The Most Common Bug on Cats
The cat flea is the single most prevalent external parasite on domestic cats, and it also infests dogs despite its name. Adult fleas live directly on your cat, feeding on blood. Both males and females bite, and once they’ve settled onto a host, they tend to stay put rather than jump to another animal unless the population gets large.
What makes fleas so persistent is their lifecycle. An adult female lays eggs on your cat, but those eggs roll off into carpets, bedding, and furniture cracks. The eggs hatch into larvae, which feed on organic debris before spinning a cocoon. The pupae inside those cocoons can wait weeks or even months for the right conditions before emerging as new adults ready to jump onto a host. This means that even after you treat your cat, a new wave of fleas can hatch from your home environment. Optimal conditions for flea development are warm, humid spaces, which is why infestations tend to worsen in summer or in heated homes.
Fleas also bite humans. Their bites cause itchy, inflamed welts, typically around the ankles and lower legs. Beyond the irritation, fleas can transmit tapeworms to cats who swallow them during grooming and, in rare cases, can spread cat scratch disease bacteria between animals.
Ticks That Target Cats
Cats that spend time outdoors are vulnerable to hard ticks from several groups, including species commonly known as deer ticks, American dog ticks, and lone star ticks. In a national U.S. survey of ticks found on pets by veterinarians, the deer tick (also called the blacklegged tick) appeared on nearly half of all infested cats, making it the most commonly recovered tick species on felines.
Ticks don’t live on cats permanently. They climb aboard from tall grass or leaf litter, attach with their mouthparts, and feed on blood. Larval ticks may feed for just two to three days, while adult females can stay attached for two weeks or longer before dropping off. On cats, ticks strongly prefer the head, ears, neck, and back, likely because cats have more difficulty grooming those areas.
Tick bites matter beyond the discomfort. Depending on the species and region, ticks can transmit diseases like Lyme disease and anaplasmosis. If you find a tick on your cat, removing it promptly with fine-tipped tweezers reduces the chance of disease transmission.
Ear Mites
Ear mites are tiny parasites, roughly the size of a pinhead, that colonize the ear canal. They’re especially common in kittens and stray cats. Though nearly microscopic, you can sometimes spot their small white bodies moving if you look closely.
The signs of ear mites are hard to miss. Infested cats scratch their ears constantly, shake their heads, and hold their ears flat. Inside the ear canal, ear mites leave behind a dark, waxy, foul-smelling buildup of debris. This gunk is a mix of wax, dead skin, and mite waste, and it’s essentially the environment where the mites thrive.
Ear mites are extremely contagious between animals through close contact. When a mite lands on a cat’s body, the cat usually grooms it away. But if the mite reaches the ear canal before being licked off, it’s safe from the cat’s tongue and paws. This is why multi-cat households often see ear mites spread through the entire group. Ear mites don’t establish lasting infestations on humans, but they can occasionally cause temporary itching.
Skin Mites and Mange
Beyond ear mites, several mite species burrow into or live on cat skin. Each causes a distinct type of problem.
Notoedric Mange (Feline Scabies)
The most common cause of scabies in cats is a burrowing mite that digs into the skin and triggers intense, relentless itching. Cats develop crusty, thickened skin, typically starting on the head and ears. The itching from this mite is extreme, rated the highest of any feline skin mite. Infested cats may scratch until they create open wounds.
Sarcoptic Mange
A related burrowing mite that primarily targets dogs and foxes occasionally infests cats. When it does, the pattern looks different from typical feline scabies. Cats develop heavy crusts and scaling, often on the head, ear edges, and lower legs, but surprisingly little itching compared to notoedric mange. This mite can also burrow into human skin, causing itchy raised lesions, though it can’t complete its lifecycle on people.
Demodex Mites
Cats host two main species of Demodex mites that behave very differently. One is a long, slender mite that lives deep in hair follicles and is generally considered part of normal skin flora. It only causes problems in cats with weakened immune systems. The other is a short, stubby mite that lives in the outer layer of skin rather than in hair follicles. This second type is unusual among Demodex mites because it’s contagious between cats and causes itchy skin disease even in otherwise healthy animals. It has been increasingly recognized in multi-cat households.
Walking Dandruff
If you notice heavy, flaky dandruff on your cat’s back that almost seems to move, the cause may be a large surface-dwelling mite. These mites live on the skin’s surface and feed on skin debris rather than burrowing. Their movement through the flaky skin creates the visual illusion of “walking dandruff,” which is actually the mites pushing epidermal flakes around as they crawl.
At about half a millimeter long, these mites are visible to the naked eye if you look carefully. Their eggs are also distinctive, wrapped in fine silk-like threads and attached directly to the hair shaft. Infestations cause a dry, scaly coat concentrated along the back. These mites can temporarily bite humans, causing itchy patches, though they don’t establish permanent infestations on people.
Lice
Cat lice are the least common ectoparasite on the list, and finding them usually signals an underlying problem. The species that infests cats is a chewing louse, meaning it feeds on skin debris and hair rather than blood. Adults are 1 to 2.5 mm long, yellowish to tan, and flat. They have a distinctively wide, triangular head that’s broader than their body, an adaptation for gripping hair shafts.
Lice infestations in cats typically appear in animals that are very young, elderly, sick, or living in unsanitary conditions. Healthy, well-groomed cats rarely carry significant numbers. Infestations are also more common in cooler months. Cat lice are species-specific, so they cannot spread to humans or dogs.
Which Cat Bugs Can Affect Humans
Not all cat parasites pose a risk to you, but several do. Fleas readily bite people, leaving itchy welts. The burrowing mite that causes sarcoptic mange can transfer to human skin through direct contact with an infested cat, producing itchy raised tracks, though the mites eventually die without a proper host. Walking dandruff mites can cause temporary itchy rashes on people who handle infested cats.
Cat parasites can also create indirect risks. Flea-infested cats may harbor bacteria that cause cat scratch disease, which spreads to humans through scratches or bites and causes swollen lymph nodes near the wound site. Ticks that drop off cats indoors could potentially reattach to a person, though this is uncommon.
Prevention and Treatment
Year-round parasite prevention is the most effective way to keep bugs off your cat. Prescription topical treatments and chewable tablets are available through veterinarians and target fleas, ticks, and sometimes mites simultaneously. These products work either by killing parasites on contact or by entering the bloodstream so that biting parasites are killed when they feed.
For active infestations, the approach depends on the parasite. Flea treatment requires addressing both the cat and the home environment, since eggs and pupae hiding in carpets and furniture will produce new fleas for weeks after treatment begins. Ear mites, skin mites, and lice are treated with targeted medications prescribed by a veterinarian. In multi-cat households, all cats typically need treatment at the same time to prevent reinfection, especially for contagious parasites like ear mites and the surface-dwelling Demodex species.