Cat Fleas


Cat fleas are small – about ¼-inch long – wingless, colored dark brown to black, and are often seen by homeowners on their pets or jumping around. Although flightless, cat fleas jump to incredible heights, which facilitates their ability to suck blood from various hosts. Flea larvae are about 1/5-inch long, eyeless and without legs.


The cat flea is known to feed on a much broader range of hosts than most other flea species. Common hosts for cat fleas include dogs and cats, plus outdoor animals such as raccoons, opossums, skunks, foxes, plus many rodents and other mammals. Such an extensive range of hosts affects even those without pets, as cat fleas can enter the home in a number of ways. An example of such a situation may occur when an infested wild animal occupies a chimney, attic or a crawl space. However, more often than not the source of a cat flea problem inside the home likely results from a pet being infested while roaming or resting outside the home and then bringing cat fleas inside.


Cat flea adults consume blood they obtain from feeding on mammal hosts. Cat flea larvae consume flea dirt, which is undigested blood that is excreted in the form of adult flea feces. Flea pupae do not feed.


Cat flea habitat and where they live depends upon the developmental stage the flea is in. Adult fleas live on their host, larval fleas live in places that are frequented by either pets or wild animals and are protected, dark and where the relative humidity is at least 75 percent and the temperature is 70 to 90°F.


Cat fleas have four, distinctly different developmental phases – eggs, larvae, pupae and adults. Generally, it takes about 3-5 weeks to complete their entire life cycle; however, this period will vary greatly depending upon favorable or unfavorable conditions of temperature and humidity in their habitat. Female adult fleas lay eggs only after they have taken a blood meal and will lay from 25-40 eggs per day. If adults do not feed, they will die in less than 2-3 weeks. Eggs are laid on their host’s fur, but soon after being laid by the female flea, the eggs drop to the ground more or less in a haphazard, unplanned manner. The egg stage lasts for about six days. 

After the eggs hatch, flea larvae live for about 5-11 days. The next stage is the pupal stage, and this stage takes about 5 days to produce adult fleas. But, under less than optimal conditions of temperature and humidity, the pupal stage may last much longer and pre-emerged adults may continue to live in the pupal case until the presence of a host stimulates the pre-emerged adult to go ahead and emerge from the pupal case and begin feeding on an available host.


Evidence of cat fleas includes the presence of flea dirt, adult fleas on hosts, biting fleas on people and pets, irritation and papules from flea bites, frequent licking and biting at fleas on the pet’s body and loss of hair.


Cat fleas can be prevented or minimized by mechanically using a vacuum to remove flea dirt, egg, larval and pupal stages and other organic debris that larvae might feed on. Also, using a steam cleaner on carpets or floors can be helpful. Killing adult and larval fleas by laundering and drying pet bedding or items that pets are in close contact with also helps reduce the number of fleas in a household. Bathing and grooming pets is a very good way to reduce the numbers of fleas inside. Outdoors, eliminating shaded portions of the yard and keeping grass closely mowed, plus reducing or eliminating rodents and other animals that can bring fleas onto the property will help add to flea prevention.


Since flea control often involves treating one’s pet, home and the exterior yard, it usually is best to seek the advice and expertise of a pest management professional (PMP) when an integrated control plan is required.

Controlling fleas on pets generally involves using insect growth regulators that interfere with the flea’s normal reproduction patterns and using veterinarian-approved “spot-on” flea control products on pets. Prior to using any pet insecticide, be sure to talk with your veterinarian regarding your pet’s health status and breed sensitivities to products.

Sometimes it is necessary to use insecticide liquids or dusts as residual sprays to control flea adults and larvae inside the home. Always be sure to follow the product’s label and directions when applying insecticides for flea control.

Outside flea control is often needed if pets venture outdoors and then come back inside the house to sleep or eat. When required, use insecticides to treat shaded areas, under decks, inside crawl spaces and around shrubs where animals may either spend time or seek out places for protection. The key to determining where to spray is to select and treat any places where pets or wild animals may inhabit.

Once a flea infestation is established, prevention and control efforts both on the host and in the host’s and flea’s environment must be made more or less within the same timeframe so the efforts completely control and prevent the flea infestation.