Are fleas black?

Summary

Cat fleas aren’t black. They’re a dark brown color. However, their feces is black or dark red, and it’s often found within dog and cat fur.

Details

Fleas Aren’t Black

Adult cat fleas are a dark brown color Img 1. While they aren’t black, fleas may appear black from a distance.

Unfed Fleas are a Dark Color

Young, unfed adult fleas are a dark brown, almost black, color. The dark coloration is caused by overlapping abdominal segments. Upon consuming a blood meal, their abdomens expand, nearly doubling in size. The segments spread out to accommodate for the growth, and the body appears as a lighter color since the segments no longer overlap.

Flea Dirt is Black

When pets have fleas, dark specks will accumulate in their fur Img 2. These reddish-black specks aren’t the insects themselves, but their feces. It’s often called flea dirt. Flea dirt is composed of undigested or partially-digested host blood. Once dry, it resembles black pepper. If moistened, the fecal blood will reconstitute, turning water into a crimson red color.

References