Fleas are a common nuisance, affecting both pets and humans. In the United States, controlling fleas can cost pet owners billions of dollars annually. Ctenocephalides felis, the cat flea, is the most prevalent species, infesting cats, dogs, and other wildlife. While fleas can be a persistent problem, understanding their life cycle and how they travel is key to effective control.
Identifying Fleas
Adult cat fleas are small, typically measuring about 1/8 inch (1 to 3 mm) in length. They have a brownish-black, flattened appearance and lack wings. Their bodies are equipped with backward-pointing bristles, which help them navigate through the hairs or feathers of their hosts and resist removal during grooming. Fleas have six legs, with the hind pair being particularly long and adapted for jumping.
Flea larvae are even smaller, usually less than 1/4 inch (6 mm) long. They are legless and have a dirty white color. Larvae are most commonly found in infested pet bedding.
Cat fleas are the most common fleas on dogs and cats
Understanding the Flea Life Cycle and Hosts
Fleas undergo four distinct life cycle stages: egg, larva, pupa, and adult. Adult fleas are capable of jumping, but they don’t typically travel long distances without a host. Instead, they prefer to wait and jump onto a passing animal. Once they find a host, they usually remain there until dislodged or groomed off. Adult fleas can only survive for a few days to two weeks without a host. Fleas on short-haired animals tend to live approximately eight days. On long-haired animals, they survive longer.
The Four Stages of the Flea Life Cycle
Within two days of her first blood meal, the female flea will begin laying eggs. On average, they can produce 27 eggs daily, consuming around 15 times their body weight in blood. A significant portion of this blood is excreted as partially digested feces, which appears as a fine, reddish-black dust in pet fur and bedding.
Flea larvae rely on adult flea excrement for food, and without it, they cannot survive. They can also feed on organic matter, such as food particles, dead skin, or feathers. Larvae develop over a period of 5 to 11 days.
Fleas struggle to survive in hot, sunny lawns. High temperatures and low humidity are detrimental to flea larvae. Relative humidity below 50 percent or soil temperatures exceeding 95 degrees F (35 degrees C) are lethal. Therefore, fleas are usually found in moist, shaded areas near where pets rest. Indoors, flea larvae are commonly found under furniture and in pet bedding.
The pupa stage is a transitional phase between the larva and adult. Pupae develop inside a cocoon spun by the larva. After one to two weeks, the pupa transforms into an adult flea. The adult flea can remain in the cocoon for up to five months, but they can quickly emerge within seconds when stimulated by a passing animal. This explains why long-vacant homes or apartments can suddenly become infested with fleas when new inhabitants move in.
Flea life cycle showing how fleas grow from eggs to larva to pupa to adult
How Do Fleas Travel and Infest?
Understanding how fleas travel is crucial for preventing and managing infestations:
- Jumping: Fleas are excellent jumpers. Their powerful legs allow them to jump significant distances, enabling them to move from the environment onto a host.
- Hitching a Ride: Fleas primarily travel by attaching themselves to hosts, such as pets, rodents, or other animals. This is the most common method of transportation for fleas.
- Human Transport: Although less common, fleas can also hitch a ride on humans, particularly on clothing or shoes.
- Within Buildings: Fleas can move between rooms in a building by jumping or crawling. They thrive in carpets, upholstery, and pet bedding.
- From Wildlife: Fleas can be introduced into yards and homes by wildlife, such as squirrels, raccoons, or stray animals.
Effects on Animal and Human Health
Fleas can cause irritation and transmit diseases. Heavily infested pets often scratch constantly, leading to skin irritation, soiled coats, and nervous behavior. Flea allergy dermatitis, an allergic reaction to flea bites, is a common and serious issue for pets. Even a single flea bite can cause intense itching and scratching in allergic animals.
Cat fleas do not typically live on humans but will bite people who handle infested animals. Flea bites on humans usually result in small, red, itchy bumps, typically on the ankles and lower legs. People allergic to flea bites can experience hives, rashes, or generalized itching. Allergic reactions typically appear 12 to 24 hours after a bite and can last for a week or more.
Fleas that have fed on rodents may carry diseases such as plague and murine typhus. It’s crucial to avoid close contact with wild rodents like squirrels, rats, and prairie dogs, as their fleas can transmit these diseases. However, cat fleas do not carry plague.
How to Get Rid of Fleas
Effective flea control requires an integrated approach that includes good sanitation and treatment of the pet and environment. While it may take time, especially with heavy infestations, you can eliminate fleas from your home with proper treatment.
Sanitation
Regularly change pet bedding and vacuum thoroughly. Vacuuming can remove up to 30 percent of flea larvae and 60 percent of flea eggs from carpets, as well as their food supply of dried blood.
Focus on vacuuming under furniture, cushions, chairs, beds, and along walls. Dispose of vacuum cleaner bags at least once a week to prevent fleas from continuing to develop inside and re-infesting the house.
A black dog laying in grass
Treating Pets
A flea comb and a bath are your pet’s first line of defense. Soap acts as a mild insecticide and helps control light infestations. While time-consuming, combing reduces the need for insecticides. Flea combs have fine teeth that remove adult fleas from fur. Most dogs and cats enjoy this treatment; pay special attention to the face and neck, and the area in front of the tail. Dip the comb frequently in soapy water or an alcohol solution to kill fleas removed from the pet.
Insect Growth Regulators (IGRs)
IGRs are a safe preventative treatment that disrupts the normal development of flea eggs and larvae. When exposed to IGRs, adult fleas are unable to reproduce; eggs fail to hatch, and larvae die before completing their development. IGRs are available as sprays, spot-ons, pills, or food additives.
Treatments for Severe Infestations
For severe flea problems, a product that kills adult fleas, such as imidacloprid or fipronil, may be necessary. These products have low toxicity to mammals and pose little risk to pets or people.
Treating Homes
Treat the pet’s living areas at the same time as the pet. This kills immature and newly emerging fleas and prevents re-infestation of the pet. Citrus sprays, boron-based products, and insect growth regulators can be used indoors.
Fleas, but No Pets?
If you have fleas but no pets, other animals like bats, roof rats, squirrels, raccoons, and wild dogs and cats might be nesting in your home and be the source of the infestation. A pest control company can treat for fleas and seal openings through which wildlife may enter your home.
Conclusion
Understanding how fleas travel, their life cycle, and effective control methods is essential for preventing and managing infestations. Regular sanitation, proper pet care, and appropriate treatments can help keep your home and pets flea-free. By taking proactive measures, you can reduce the risk of flea infestations and protect the health and well-being of your family and pets.
