Technical Papers

New Jersey Homeowner's Guide to Fleas

Wednesday, February 17th, 2016 by Bill Cowley


A flea is a parasitic insect that can be found throughout the United Sates. They are well known for feeding off of dogs and cats, however fleas can feed on any warm blooded animal, including humans. There are over two thousand species of fleas world-wide, butdog itching flea the most common species in the United States is the Cat Flea. Although the name would suggest that these insects are found on cats only, these fleas can be found on a wide variety of warm blooded animals throughout New Jersey and most all of North America.

Physical Characteristics:

Fleas are relatively small flat insects. The average flea is one twelfth to one sixth of an inch long with six legs and antennae. Fleas are a dark red-brown color and this color does not change significantly when the flea engorges with blood.

Unlike many other insects, fleas do not have wings and therefore are unable to fly from one place to another. In order for a flea to change locations, it either travels from one area to another on a host animal or it uses its exceptionally strong legs to jump. The average flea can jump roughly 8 inches. This means that a flea can jump approximately one hundred fifty times its own height. If the average human was able to jump one hundred fifty times his own height, he would be able to jump over a skyscraper. 


The average flea lives for approximately one hundred days. In that amount of time a single female flea could produce 400-500 offspring. Like a butterfly, a flea’s lifecycle consists of four distinct phases: egg, larva, pupa, and adult. A female flea will begin to lay eggs within two days of her first blood meal. Between four and nine days after that meal she will begin to lay an average of 27 eggs per day. During this time she will consume about fifteen times her own body weight in blood every day.

The flea will not fully digest the blood she consumes. In fact, much of the blood that is consumed is then excreted as partially digested feces which are the reddish-black dust seen in infested pet fur and bedding. These partially digested feces become food for flea larvae that need to ingest adult flea excrement in order to survive. The flea larvae develop within five to eleven days. If flea larvae are found indoors it is usually under furniture and in pet bedding.

The next phase of flea development is the pupa stage. The pupa phase is the transition stage between larva and adult. Like a butterfly, the pupa forms inside a cocoon that is spun by the larva. The pupa will stay inside the cocoon for at least one week.  The pupa becomes an adult after one to two weeks inside the cocoon. Although the flea has become an adult after this time, it may remain in the cocoon for up to five months. It will often wait in the cocoon until it is stimulated to come out by a host passing by. The adult flea can emerge from its cocoon in seconds.  This ability to lie in wait until a suitable host appears is why some vacant apartments or homes can “come alive” with fleas when new owners move in.


Although a flea has the ability to jump a relatively far distance, adult fleas don’t usually travel far without a host. Fleas usually prefer to wait until a host travels past them and then they jump directly onto the new host. Once the flea is on the host animal it will usually remain there until it is dislodged or groomed from the animal. Fleas do not live very long outdoors on hot, sunny lawns. If the relative humidity is less than fifty percent or soil temperature higher than ninety five degrees Fahrenheit flea larvae will die. Some flea larvae may be found outside in a moist, shaded spot near a pet’s resting areas.

Fleas consider household pets, wild animals (like rodents, opossums, raccoons, and skunks) and even humans to be possible hosts. Fleas are also found in areas close to where hosts may be such as pet bedding, blankets, and even on shoes or pant legs. Their propensity to be in shoes or on pants allows fleas to move to new environments easily. Without a host, adult fleas live only a few days to two weeks.

Flea Concerns for NJ Homeowners:

Although fleas are very small, they can be very dangerous. Fleas are the vectors of many diseases including the bacterial disease Murine Typhus and the Bubonic Plague that ravaged Europe many years ago (although the Cat Flea, the most common flea in the United States, does not carry the plague). Fleas can also transfer tapeworms to their host. In pets, fleas have been known to cause anemia. Fleas can stay on a host (human or animal) when their host travels. Due to the vast amount of cross continental travel on both boats and airplanes, fleas can infest vast expanses.

Although cat fleas do not normally live on humans, they will bite a person if the person handles infested animals. In humans, flea bites usually cause small, red, itchy bumps. These conditions are most commonly found on people’s ankles and calves. Some people are allergic to flea bites. If this is the case the person often suffers from hives, rashes or generalized itching. People who are allergic to flea bites will usually see symptoms 12-24 hours after the bite. These symptoms can last more than a week.

New Jersey Flea Control:

Americans spend about $9 billion a year protecting their homes and pets from fleas. There are a number of precautions homeowners can take to reduce the chance of fleas in their New Jersey homes. Inside a home it is important to vacuum frequently in order to remove fleas and remove flea eggs before they can hatch. Outside, lawns should be cut frequently in order to make them inhospitable to rodents. Fleas live on many wild animals, including rodents. Having rodents in close proximity to a home increases the chance of being infested with fleas.  If there is a pet in the home, the owners should make sure to bathe and groom the pet regularly and visit a veterinarian annually in order to make sure flea treatments are working properly.

A home or building can be infested by fleas even if there are no pets on the premises. Wild animals such as bats, roof rats, squirrels, and raccoons will nest in homes if given the chance and they can be the source of an infestation. If there is an infestation it is important to contact a qualified pest control professional that practices Integrated Pest Management (IPM). They will be able to both treat the fleas that are on the property as well as close any openings through which wildlife may have entered the building.