The Flea, just like the Bedbug, is a blood-sucking vermin. Fleas are small, dark-colored, wingless parasites which reach up to 4mm in length. They have flat, oval-shaped bodies which allow them to jump over distances over 33 cm long. They have tube-like mouth-parts, suited for feeding on the blood of their hosts.
Although Fleas rarely feed exclusively on humans, Flea bites can still pose a serious health hazard. Fleas are known to spread a variety of diseases, such as Typhus, Tularemia, Bubonic Plague, and Cat Scratch Disease. Typhus and Bubonic Plague are notorious for their mortality rates. Still, it is not likely for a human to be infected with them in the UK (due to vaccination and high hygiene standards).
Cat scratch disease is a common and real health threat. It is caused by the Bartonella Henselae bacteria and puts people with a weakened immune system at serious risk. It can result in muscle pains, enlarged lymph nodes, reproductive issues and deep inflammations and infections.
Fleas are also known to transmit various kinds of Tapeworms, especially between animals.
Fleas feed only on bird and mammal blood. Although different types of Fleas prefer different hosts, they all bite humans. The main host of choice for the most common species are Dogs and Cats. Their saliva prevents the immediate detection of the bite. Later it causes severe irritation and itching. Adult fleas locate their hosts by movement, vibrations and animal breath (through warmth and humidity differences in the air, etc.).
Fleas also have larvae which feed on the organic and fecal matter. Although they are hatched blind, they can detect adult fleas’ excrements—a sign of a food source nearby.
Depending on the stage of their life cycle, fleas choose to live in different conditions.
Flea Eggs: Dozens of them are laid directly on your pet’s fur every day and fall spread wherever your pet brings them, which means flea eggs can end up in your bedding, furniture, carpeting and even on top of appliances (if you have a cat, you can be sure of it).
Flea Larvae: They like dark, narrow and dusty spaces that offer protection during this immature stage. Flea Pupae are found only on floors and in-between carpet fibre. Despite composing just 10% of a flea population, they are the main reason why Flea treatments often fail.
Adult Fleas: As adults, Fleas hide only on live hosts such as Cats, Dogs, Rodents and any other furry mammal.
In your yard and in wildlife, Fleas live in high grass, sand, sheds, and debris – places where they can find shade and humidity. These areas, such as the grass underneath a shrub, provide the perfect conditions for all three stages of the flea’s life cycle. From the egg lay to the cocoons – and that’s not all. Animals also prefer to go in the shade on hot summer days, and that’s the time for the newly hatched adult fleas to go for a snack!
The most densely infested areas on your pets’ bodies would be around the neck, ears, and underbelly. An even better question is where do Fleas come from? A Flea infestation can take place even if your pets always stay indoors, as your own vibration and heat can attract a Flea while you are enjoying a picnic, fishing trip or just a stroll in the high grass.
Nonetheless, humans cannot actually get Fleas – not the common household Fleas at least. There’s a species called the Human Flea, Pulex irritans, that live on humans, Pigs and other mammals that don’t have fur. Those are encountered only in the wild, however, are different from the fleas found on your Cats and Dogs.