What’s the difference between bed bugs and fleas?
Knowing whether you’re facing off with bed bugs or fleas can make a lot of difference in who you call and how you proceed. Here’s how to tell.

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If you’re not really sure if you’re dealing with bed bugs or fleas, you’re not alone: A survey of pest exterminators revealed that around two-thirds of their customers’ calls about a “flea problem” turned out to be a bedbug infestation, according to pestworld.org. Here’s how you can tell whether you have bed bugs or fleas.
Fleas are smaller
They’re both out for blood—but are the bugs biting you bed bugs or fleas? Brown to reddish brown in color, fleas are smaller than a bed bug—they’re sesame-seed sized and they’re what scientists call bilaterally flattened—they’re taller than they are wide, says urban entomologist Jody Green, PhD, at the University of Nebraska-Lincoln. Bed bugs are more like a pancake (dorsoventrally flattened), explains Green. They’re brown to brownish-red depending on their last blood meal. Their size and shape also change depending on their stage in life and how recently they fed on you: See for yourself how big bed bugs really get after a blood meal.
They start life differently
“Fleas go through a complete metamorphosis of egg, larva, pupa, adult—and only the adults feed on blood,” says Green.”Bed bugs have an incomplete metamorphosis of egg, nymph, adult—and nymphs and adults feed on blood.” Spotting bed bug eggs will help you detect an infestation faster—here are what bed bug eggs look like.
One jumps, one crawls
Think a moment: Are bed bugs or fleas known for they’re jumping ability? Yep, it’s the fleas—bed bugs are plodders. Both pests have six legs, says Green, but fleas’ femurs in their hind legs are enlarged to aid their jumping ability. According to the University of Missouri Extension, an adult flea can jump up to eight inches vertically and 16 inches horizontally. Bed bugs have no such specialized appendages, so they get around by crawling. But can bed bugs fly? Read this next to find out.
One lives on a host; one has its own house
You’ll be happy to know that neither bed bugs or fleas take up residence on humans. But fleas do like a live host—a warm-blooded animal like your cat or dog, or wild creatures like squirrels, rats, and other wildlife. “Fleas have backward-facing spines to navigate through the hair of animals,” says Green. Their backward-facing spine also makes them difficult to remove when you’re grooming your pet.
Bed bugs only need to be near their blood meal, so they hide during the day in what’s known as a harborage—a wall, nook, or dark space near your bed; at night, they’ll crawl up the legs of your bed and feast on you. Once they are engorged, they waddle back to their harborage. Here’s what a bed bug harborage looks like—and other signs of a bed bug infestation.
Are these bites from bed bugs or fleas?

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Both bugs live of mammal blood, but bed bugs prefer human, fleas have a taste for animals. Bed bug bites can be just about anywhere on your body, and the kind of reaction you’ll get can range from unnoticeable to angry welts: It just depends on whether you react to proteins in the bugs’ saliva. Typically, bed bug bites come in groups of three—clusters or rows. Most often, people get red bumps that itch; the bites can appear as welts or blisters.
While fleas prefer your cat or dog, they won’t turn down your ankles if they’re handy. Fleas tend to infect your carpet or floors, and they’ll jump onto your lower legs. For that reason, their bites frequently appear below the knee. Of course, if you lay on the floor or your infected pet spends time in your lap, you’ll get bites higher up. The bites typically look like small bumps with a red halo; they can also appear in groups of three and will be extremely itchy. Resist the urge to scratch—check out these 8 home remedies for itchy skin instead.