Flea Facts, Identification and Control
Scientific Order: Siphonaptera
Common family: Pulicidae
Cat flea (Ctenocephalides felis)
Dog flea (Ctenocephalides canis)
Human flea (Pulex irritans)
Oriental rat flea (Xenopsylla cheopis)
Size: Very small; 1/12 to 1/4 inches (2.12 to 6.35 millimeters)
Color: Can include dark brown, black, brown-black, gray, or dark red-brown. Often semi-translucent
Behavior and Diet
Fleas are parasitic insects that feed on mammals, including humans and pets. Most species of flea prefer to feed on a specific type of host. Fleas derive their common names from their preferred hosts. All common flea species can feed on humans.
Unlike ticks or most other pest parasites, fleas do not permanently stay latched onto their prey, and may jump on and off of a host repeatedly. They attack hosts by leaping directly onto the host and then climbing to a bite-vulnerable area of the body.
Reproduction and Life Cycle
Mature female fleas usually lay eggs directly on a host they are actively feeding on. These eggs aren’t attached to the host, however, and generally fall off and continue to incubate on the ground or in the host’s home. If a pet has fleas, for instance, it’s probable that there are flea eggs in its bedding.
Fleas lay eggs after every blood meal. Some species lay only 4 to 8 eggs per meal, while other species may lay up to 25. Most fleas lay several hundred eggs in their lifetimes. A flea’s life cycle is broken into four distinct developmental stages: egg, larva, pupa, and adult. Life cycle development depends on temperature and food availability and could take anywhere between a month to 200 days or more. Adult fleas may live for a year or longer.
Signs of Infestation
Flea bite scabs are small, black- or rust-colored spots that may be inflamed or puffy. They resemble mosquito bites, but they're usually slightly darker. Fleas usually bite around the shins, neck, or ears. Flea bites don’t usually swell, but they may itch or turn red. Look for patterns of 2 to 3 bite marks in close proximity.
Look for flea eggs in any animal housing or bedding. Flea eggs look like tiny, grainy or sandy grey or black buildup. They may resemble dust or salt and pepper.
Treatment and Prevention
Vacuum thoroughly and frequently. Consider having your carpets shampooed and/or steam cleaned to remove any larvae or eggs that may be hiding in them. Dust surfaces frequently, especially in dark areas of the home that aren’t often accessed, such as a basement or cellar.
Practice humidity control and consider investing in a dehumidifier for vulnerable areas. Mop hard floors frequently, and make sure to dry them thoroughly when you’re finished. Do not allow lawn debris or garbage to accumulate in piles near your building.
New York City Department of Health and Mental Hygiene’s Flea page
Cornell University Department of Entomology’s Flea Insect Diagnostic Laboratory fact sheet
Penn State College of Agricultural Sciences Department of Entomology’s Cat Fleas Insect Advice Extension page