What Color are Fleas?

One of the most common questions cat and dog owners have about fleas is “What color are fleas?”. Users often search for this information when they want to identify the type of insects that bite and nuisance their pets and sometimes people themselves. This article will answer that question and other common ones, while also providing helpful tips for managing fleas.

What Color are Fleas?

Fleas are known for their exceptionally small size, but flea color provides a way to differentiate them from other tiny insects. There are many flea species around the world, and fleas’ colors can range from white to brown. Fleas come in a variety of colors including black, brown, white, yellowish-brown, reddish-brown, and dark brown. Some flea species even have spots or stripes on their bodies that provide camouflage in different environments!

What color are fleas?

A flea appears to be a small, dark-colored insect. Fleas come in many different colors, depending on their age and what they have been eating.

Here is a list of some common flea colors:

  • black;
  • brown/medium-dark brown;
  • light tan to medium golden blonde;
  • grayish-white;
  • or pinkish-red.

There are other possible variations too! In addition to these basic fleas’ color shades, there can be faint stripes from blood meals taken just before feeding, reddening caused by irritation from grooming at bites sites (or scratching because you keep finding new ones), plus dark staining around eyes and mouthparts (from digested blood).

Newly emerged adults tend to be darker, almost black in color. The reason for this is that unfed fleas overlap each other’s abdominal segments. When they consume blood, their abdomens double in size. When the feeding is complete, the segments are no longer overlapping. When this occurs, their bodies appear a lighter brown color.

Glossy and Shiny Appearance

Cat fleas appear glossy and shiny. This is because fleas are covered in an oil-like outer secret from their numerous pores on the front part of their bodies. Fleas move through host hair due to the secretion of a substance from those pores. Also, this allows fleas to survive outside of hosts for many hours and even days if it’s cool enough.

Color of Most Common Flea Species

Human Fleas

The fleas that live on humans tend to be a dark grey or black color. Adult human fleas (Pulex irritans) can reach a length of 4 mm, making them slightly larger than cat and dog fleas.

Cat Fleas

Cat fleas (Ctenocephalides felis) are generally flat with dark-colored heads, while fleas of dogs are larger with big heads. Cats fleas are generally reddish-brown to dark brown in color with a small body about 1/16 inch long.

Dog Fleas

Dog fleas (Ctenocephalides canis) are generally grayish brown to brown in color with a large body about 3/8 inch long.

Sand Fleas

Sand fleas generally have a dark brown body and an orange head, while fleas living on human bodies are usually pale yellow to grayish-white in color. They tend to prefer dry climates such as the Sahara Desert, where their diet consists mainly of dead animals and plants.


The answer to the question “What color are fleas?” is that they have a variety of colors, depending on what type of environment they live in. In general, most types of wild or feral cats can be found with black and brown colored fur so it’s not surprising that their pests would also reflect this same pattern.


  • What is the most common flea color?
    Dark brown.
  • What color are flea eyes?
  • What flea colors are rare?
    Pale yellow, dark brown/black with spots of white or gray on the back.
  • What flea color is best for hunting mammals?
    Fleas' body color can vary depending upon what mammal they're preying on and whether they live indoors vs outdoors. For example, fleas that live outdoors, away from the direct light of the sun tend to be dark brown or black.
  • Do fleas change colors as they grow?
    Fleas start from a very pale yellow color and will progressively darken as they grow.
  • What flea colors are best for hunting birds?
    Pale yellow with an orange head and black spots on their back. The female fleas' abdomen is usually longer than it is wide, while males have a more rounded abdomen.
  • What flea color is best for hunting rodents?
    Fleas that are dark brown or black. Dark colors help the fleas blend in with rodents' fur to avoid being detected by their victims, therefore increasing their chances of survival.
  • Are white fleas sick?
    No. It is possible for fleas to be bright white, off-white, or translucent.
  • Do fleas have spots?
    Yes, flea bodies can be spotted with different colors including black, white, or gray. The size of the flea's body is not associated with its age or how long it has been feeding on its host because adult flea bodies change in shape and size throughout their development.
  • What flea color is best for hunting rabbits?
    Fleas that are dark brown or black.
  • Do fleas change colors as they grow?
    Yes, fleas start from a very pale yellow color and will progressively darken as they grow.
  • References

    Franklin Jones
    I'm Franklin Jones, the guy behind PestStopGuide.com. Here’s where I write all the DIY pest prevention, removal and extermination tricks.