Types of Fleas

There are believed to be well over 2,000 different types of fleas throughout the world. The most common of these wingless parasites are the following:

  • Cat fleas
  • Dog fleas
  • Human fleas
  • Oriental rat fleas

You might be shocked to read that there is such a thing as “human fleas” because we most often think of fleas in the context of living on cats and dogs and jumping on to humans to feed whenever the opportunity arises.  But, yes, there are human fleas and we will get to that in a minute.

What Do Fleas Look Like?

With there being so many different types of fleas please understand that though we will give a general description below that there are variances in many of these characteristics.

Fleas do not have wings and are thus unable to fly around.  Instead, they move primarily by jumping with powerful legs.  They can jump approximately 8 inches which is more than 150 times their height and would be the equivalent of the average human being jumping nearly 1,000 feet into the air.  They also move with the assistance of their hosts (animals or humans) transporting them from place to place.  Fleas are very dangerous when it comes to the spreading of diseases because they hitch rides on the fur of their hosts like humans ride airplanes and they can therefore infect vast expanses of lands as was the case with the Bubonic Plague that ravaged Europe.

Their bodies are usually squished like a vertical pancake making it very easy for them to weave in and around the hair follicles on animals.  They also possess backward facing hairs and barbs on their little bodies that allow them to keep their grasp on animals even when they attempt to scratch themselves to remove the pests.  They generally tend to be reddish-brown in color and possess very strong exoskeletons that make it difficult for them to be squished or killed.  When a human being tries to crush a flea between their fingers, the flea often jumps away unscathed.

Cat Fleas (Ctenocephalides felis)

The cat flea may very well be the world’s most populous flea and responsible for most of the “flea damage” the human race incurs.  It doesn’t take a rocket scientist to figure out that the primary host for cat fleas are domesticated cats.  However, the cat flea can live on a wide variety of hosts, including dogs.  Some have stated that you are actually more likely to find a cat flea on a dog than an actual dog flea.  They are also apt to bite humans.

Cat fleas are about 2 millimeters in length when full grown and have a four-stage lifecycle. Adult fleas lay wet eggs that attach themselves to the skin and hair of the host. As they dry, the eggs will generally drop off into the bedding/resting area of the host.  The eggs hatch into larvae and feed on organic material (dried blood and adult flea feces which contain blood) in the area where they hatch.  As juvenile growth hormone in flea larvae decreases they morph into flea pupae and the enter adulthood and reproduce all over again.

Dog Fleas (Ctenocephalides canis)

The dog flea may be the Rodney Dangerfield of fleas with the cat flea greedily bogarting canines, too.  Dog fleas are fairly rare in America and are more often found in Europe.  And the anatomical differences are generally only identifiable under a microscope.  Wikipedia states:

The dog flea can be distinguished from the very similar cat flea by its head, which is anteriorly rounded rather than elongate, and the tibiae of its hind legs, which exhibit eight setae-bearing notches rather than six.

So, though there are intrinsic differences between the cat and dog flea, you will be hard-pressed to see them and for all practical matter there is very little difference in how they impact the health and well-being of humans and animals.  With that said, they do carry and transmit some different diseases.

Human Fleas (Pulex irritans)

Believe it or not, there are human fleas.  Thankfully, due to proper hygiene and improved sanitation efforts in America, the presence of human fleas on actual humans is incredibly rare.  In fact, you are far more likely to find them on domesticated pigs.

A website devoted to discussing fleas and their interactions with humans states:

Adult Pulex irritans are reddish-brown and the largest females can be one and half times the size of the smaller males.  Also, the abdomen and thorax of the human flea are larger than the head which is much smaller in proportion to its overall body size.

Believe it or not, guinea pigs may have been the original host for human fleas as it is believed that they originally hail from South America.

Oriental Rat Fleas (Xenopsylla cheopis)

The Oriental rat flea feeds on rodents and is also referred to as the tropical rat flea.  They are incredibly dangerous in that they can be carriers of bubonic plague and murine typhus.  Though each of the preceding fleas carry diseases of their own, the Oriental rat flea is far more deadly.  This is the flea believed to be responsible for spreading the plague throughout Europe and may have resulted in nearly 200 million deaths.

The Oriental rat flea tends to be a smidge larger reaching sized of 2.5 millimeters and Wikipedia states:

The Oriental rat flea has no genal or pronotal combs. This characteristic can be used to differentiate the oriental rat flea from the cat flea, dog flea and other fleas.