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Flea Problem?

Updated: Sep 20, 2022

What you need to know about Fleas (Siphonaptera)

Greek siphon 'hollow tube' + a 'without' + pteron 'wing' (fleas are wingless and have tube-like mouthparts)

Fleas, the bane of late summer existence. Want to get rid of them? Let’s explore what makes them tick so you can finally understand how to get rid of them and keep them gone. Note: putting flea preventative on one time doesn’t do much. Read further to find out why!

The adults feed on the blood of mammals (~90%) and birds (~10%); larvae, on organic debris, including adult flea feces (which contain undigested blood), and dead mites. Most fleas spend a considerable amount of time away from their host. Adults may live for two years or more and can survive for weeks or months without a blood meal.

The entire life cycle of a flea can require two weeks to two years. The hot, and humid months of summer favor egg laying. Hot, dry periods give maximum adult production, so greatest adult flea populations are produced in August to September.

The Life Cycle

The beginning of the life cycle occurs when an adult female flea lays eggs following a blood meal, which is necessary for the adult flea to reproduce. Eggs are laid in the host nest, bedding, carpet, upholstery, or cracks in the floor, usually hatching in 7 to 14 days. The eggs are small and white (slightly smaller than a grain of sand). Some fleas can lay 500 eggs over a period of several months by laying batches of three to 20 eggs at a time. Eggs can hatch in as little as 2 days with warm temperatures and high humidity. Eggs represent about one-half (50 percent) of the entire flea population present in an average home.

The emerging larvae avoids light and feeds, by eating pre-digested blood (known as flea “dirt”) that adult fleas pass, along with other organic debris in the environment. In appearance, flea larvae can be up to ¼-inch long, without legs and appear white in color. Larvae make up about 35 percent of the flea population in the average household.

If conditions are favorable, after a larval period that includes two molts, the larvae will spin thin silken cocoons in about 5-20 days of hatching from their eggs, becoming pupae. Under excellent conditions the life cycle from egg to adult flea can be completed in less than a month. Cocoons have a sticky outer coating that allows them to hide deep in the carpeting and not be easily removed by light vacuuming or sweeping. The cocoon also serves to protect the developing adults from chemicals, making it the hardest to eradicate.

The adult flea will emerge when the presence of a potential host is made obvious - by vibrations, rising levels of carbon dioxide, and body heat. Fleas are known to remain in the pupal stage from five days to five weeks in the absence of hosts. Adults emerge from the pupal case when alerted that a host is nearby. This is one reason why people returning to an unoccupied home may suddenly be attacked by an army of fleas. The pupae stage of the flea life cycle accounts for about 10 percent of the flea population in a home.

Eliminating Fleas

Use your knowledge of the flea life cycle to eliminate an infestation. Treat the environment properly by vacuuming regularly for several weeks and thoroughly washing bedding and toys in hot soapy water to remove eggs, larvae, and pupae. Remember to seal and remove vacuum bags after a cleaning session. You can even encourage faster emergence of the remaining pupae with a humidifier and a slight increase in the home temperature.

We encourage the use of year-round flea and tick control preventatives. We also, in the case of a severe infestation, recommend using a spray for your floor and carpets like Knockout, to remove populations faster.

Fleas can be difficult to eliminate, but if you are vigilant and use chemicals in a safe and effective manner, you will win. Just be sure to treat all the areas where your pet spends time, including the car.

If you have any questions or concerns, especially regarding your pet’s health or age, your veterinarian can help you make the best decision for treating your pet.

Things you may not know about fleas:

-Fleas typically only infest animals that have a regular nest site, which is why most rodents (rats, mice, etc.) have fleas but most ungulates (cows, horses, deer, etc.) do not.

-Some fleas can jump 200 times their body length.

-Flea infested pets bite and scratch themselves constantly. Their coats become roughened, and the skin can become infected. Symptoms of sensitized hosts are often mistaken for mange.

-The laterally flattened body allows easy movement among the host's fur or feathers, and backward-pointing bristles of the hard cuticle prevent fleas from falling off or being easily captured by the host. Fleas may be extremely irritating to the host, causing skin inflammation and itching.

-Fleas transmit pathogens that cause disease in humans and other animals. Some fleas are intermediate hosts for tapeworm (Dipylidium caninum) that infects dogs, cats, and humans. Others spread a myxomatosis virus within rabbit populations, and the Oriental Rat Flea is the primary vector of Y. pestis, the bacterial pathogen for bubonic plague.

Sources: Iowa State University Dept. of Entomology, article by Jennifer Kvamme, DVM, via PETMD, and Library of Congress.

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