Fleas vs Bed Bugs: What’s the Difference?

Written by Rebecca Bales
Updated: September 19, 2022
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Key Points

  • Some key differences between fleas and bed bugs include: their bodies, their size, and their bites.
  • Both bed bugs and fleas both feed on human blood. Fleas feed on mammal blood as well as human blood.
  • Fleas jump while bed bugs do not.
  • Bed bugs do not spread diseases, however, fleas can and do.

Fleas and bed bugs have similarities in that they are both common household pests, bite people, and are hard to get rid of. Some people might experience both types of infestation with double the trouble. How can you tell the differences?

Read on to learn the facts about the size, bite, color, speed, and signs of each for proper identification of fleas vs bed bugs as well as treatment and prevention.

Comparing Fleas vs Bed Bugs

Bed bugFlea
TaxonomyOrder HemipteraOrder Siphonaptera
DietHuman bloodMammal & human blood
SizeApple seedDot
HabitatBeds, furniture, fabrics; homesPets, mammals, birds outdoor/indoor
Spread byPersonal itemsPets, outdoors
Lifespan6-12 months5-18 months
BodyFlightless wings, dark reddish-brown colorWingless, long legs, dark, proboscis, eyespots
BitesItchy welts; 4-5mm; upper halfItchy welts; 1.5-3.3.mm; lower half, crevices
Spread disease?NoYes
TreatmentHeat, cold, pesticides, laundering, cleaningPesticides, laundering, cleaning
Signs ofStains, blood, eggs, larvae, adults, odor, bitesBlood, adults, bites
PreventionPrecautionsPrecautions, flea treatment for pets

The 6 Key Differences Between Fleas and Bed Bugs


One of the similarities between these two pests is that they are small. But because “small” is relative, we need to know their precise measurements. One of the differences is that fleas are smaller than bed bugs and look like dots. They measure 1.5-3.3.m long. Bed bugs are four to five mm long and are about the size of an apple seed. They are visible to the naked eye, whereas fleas are the size of dots and are hard to see, especially with their speed.

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Bed bugs and fleas are similar in that they are parasitic insects. Their diet is hematophagy, and the facts about it show that they need blood to survive. Some species prefer certain animals. Once past Class Insecta, however, all we see are differences for easy identification.

Bed bugs are in order Hemiptera, and fleas are in Siphonaptera. We can see their differences physically in their appearance and movement — bed bugs have mouthparts, flightless wings, and they crawl, whereas fleas have a proboscis, long legs, and jump. It is easier to catch bed bugs as opposed to fleas because of their differences in speed — bed bugs move slowly, but catching fleas is a high-speed chase. Another one of their similarities is that bed bugs and fleas might both be dark reddish-brown, but bed bugs can be paler colors if they haven’t fed and fleas tend to be darker, even a dark-brown or black color.


The appearance of bloodstains is common for both. They also both have bites of itchy welts, but bed bug bites are on the upper half of the body, and flea bites are on the lower half. The identification of an infestation for bed bugs is easy — pale yellow-white eggs, eggshells, larvae, and dark adults are visible to the naked eye. Squashed bed bugs will also leave reddish-brown stains. Signs of fleas are the appearance of bites or adults jumping around.

Flea bites are smaller and seem to appear bright red in color on the skin. These types can appear very similar to bed bug bites. Bed bug bites however, are slightly larger, and while they still appear as red welts, they’re not as brightly colored as flea bites tend to appear.


Even though they’re equally present and frustrating when there’s an infestation of either in your home, they don’t spread the same way. Sure, people and pets can spread fleas to another building just as they can bed bugs. But bed bugs hitch a ride in your belongings and fleas come from your outdoor pet or someone else’s pet. Bed bugs ear the blood of birds and mammals, with some species preferring humans. Fleas eat the blood of mammals, including bats and rats. Bird and bat or rat nests are other ways of spreading bed bugs and fleas, respectively.

Spread Disease?

Bed bug bites are uncomfortable and can lead to sleepless nights just as much as flea bites. However, facts about bed bug bites show that don’t cause disease. Flea bites can, though. The black plague was spread by Oriental rat fleas.

How to Get Rid of Bed Bugs and Fleas

The methods for how to get rid of each can be pretty similar — pesticides, laundering, and cleaning. It overlaps with treatment, which means dealing with bites and the skin of the affected people or animals. Then there’s prevention, which is making sure they don’t come back.

For the treatment of bed bugs, hot or cold room treatments by commercial HVAC services are effective for all life stages.

Pesticides interrupt the bed bug at various life stages. Vacuuming and cleaning are necessary for both. Dish soap instantly kills fleas.

Diatomaceous earth is effective against both while vacuuming after applying salt or baking soda to the carpet gets rid of fleas.

Next Up…

  • Do Bed Bugs Fly? – Are you concerned you might have bed bugs? Do they fly? Everything you need to know here!
  • The Different Types of Bed Bugs – There are many of different species of bedbugs, but how many exactly? Learn now!
  • Do Bed Bugs Jump? – Can bedbugs jump from bed to bed? How about from person to person? Keep reading to find out!

The photo featured at the top of this post is © D. Kucharski K. Kucharska/Shutterstock.com

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About the Author

Rebecca is an experienced Professional Freelancer with nearly a decade of expertise in writing SEO Content, Digital Illustrations, and Graphic Design. When not engrossed in her creative endeavors, Rebecca dedicates her time to cycling and filming her nature adventures. When not focused on her passion for creating and crafting optimized materials, she harbors a deep fascination and love for cats, jumping spiders, and pet rats.

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