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Identifying Fleas vs. Bed Bugs

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Suffering from an itchy, swollen bug bite can be painful and annoying—especially when it happens continuously. The best way to prevent future ones is to know what exactly is biting you. Fleas and bed bugs are common culprits, but you should deal with them in different ways to prevent a full-blown infestation.

Here, we’ll show you how to identify a flea and a bed bug based on their appearance, bite, and more. If you have a flea problem, treatment is pretty standard with veterinary drugs. However, if it’s bed bugs that are biting you, you’ll need to call in a professional pest control company.


Fleas and bed bugs are both small, reddish-brown, blood-sucking pests. While it’s unlikely you’ll get the opportunity to look at them side by side in real life, it’s helpful to know the difference between how the two look. If you want to be sure, stick the bug on a piece of tape and hold it against a white background to get a better look.

Fleas are oval-shaped pests that range from 1.5 to about 3 mm long. Bed bugs, however, have a flatter seed-like shape and clock in at 1.5 to 5 mm.


Fleas and bed bugs differ in their choice of host. Fleas prefer to feed on hairy animals like dogs and cats, while bed bugs prefer to get straight to the skin of humans. Because of this, it’s likely that if your home has fleas, your pet brought them in, and if your home has bed bugs, a person brought them in.

That’s not to say fleas will never feed off people and bed bugs will never feed off animals. If they need to, each pest will feed off their second choice to survive.

How they Move

Fleas are known to jump an impressive distance—13 inches horizontally and 7 inches vertically. Bed bugs can’t jump and instead move by crawling.

Where they Hide

Both fleas and bed bugs are nocturnal. Fleas will cling to their host, likely your cat or dog, and hide there when not feeding. Bed bugs will scurry into your mattress, box spring, and bed frame during the day to stay out of sight.

Identifying a Bite

There are some key differences between flea bites and bed bug bites, in terms of everything from where they bite, the patterns, and the symptoms.


Flea bites immediately swell up and start itching. Worse, if you’re allergic, you may get hives or a rash, and the bite may blister. Be careful not to scratch it—if the blister breaks, you may get an infection. Fleas can also burrow into your skin to feed. Luckily, the flea will die after roughly two weeks, but it may cause a skin infection.

Unlike flea bites, you probably won’t notice a bed bug bite until much later. You may feel a slight burning sensation before the itching starts. The red welts may not appear until 48 hours to a week after you were bitten. If it’s bad enough, your bite may become inflamed.


When fleas bite people, they tend to go after warm, moist areas like the bend of your elbows and knees, or your armpits and other folds in the skin. Bed bugs, on the other hand, bite exposed skin on your upper body, typically your face, neck, and arms.


Flea bites look like groupings of mosquito bites, often in clusters of three. They can turn into blisters or open sores in about three days. Bed bug bites often leave three or four bites in a row or straight line, but not always.


Because of how fleas puncture your skin, there may be a dark red center in the middle of the dot. Bed bug bites will look like raised welts from the allergic reaction people have to the pests’ saliva. Bed bug bites tend to be slightly larger than flea bites.


Fleas will bite often, whenever they get the chance for a meal. Bed bugs don’t need to feed as frequently. They eat about once a week, or every five to 10 days.


Except for the case of an infection, when you may need to see your doctor, flea bites and bed bug bites are easy to treat. Resist the urge to scratch either. For flea bites, apply a calamine lotion or anti-itch cream.  An ice pack and oral histamine may reduce the swelling. Treat a bed bug bite with a topical steroid.

If a flea bite or bed bug bite doesn’t go away after a week or two, call your doctor.


Generally, an adult flea will live for about three months. Though, under ideal conditions, fleas could live up to as long as a year and a half. A female flea will lay up to 50 eggs a day. Bed bugs have a much longer lifespan. Adult bed bugs can live for about six months to a year. A female bed bug can lay up to 500 eggs in her lifetime.


Fleas can spread diseases like typhus and tularemia, while bed bugs are not known to transmit any.

Signs of an Infestation

If you’re consistently finding bites, you need to make sure there is no flea or bed bug infestation. There are key clues.

Flea infestation

  • Multiple visible fleas on your pet or in your home
  • Clear, yellow flea eggs on your pet’s fur
  • Dark black specks of feces on your pet’s fur or bedding
  • Changes in your pet’s health
  • Changes in your pet’s behavior, like anxiety or itching

Bed bug infestation

  • Visible bed bugs
  • Rust-colored bed bug excrement
  • Bed bug exoskeletons
  • Musty odor


Generally, the treatment of fleas is easy as it gets. Bed bugs, however, are a different story.


If your pet has fleas, take it to the veterinarian to explore your options for flea medicine. Many types kill fleas at all stages of the lifecycle and are waterproof. Wash your pets’ bedding and toys, and you should be rid of fleas. If the problem persists, you’ll need to contact a pest control company.

Bed bugs

Battling bed bugs is nowhere near as simple. While you could tackle the problem with a vacuum, steam cleaner, and a variety of chemical insecticides on your own, but that’s not the safest—or most effective—route. If you have a bed bug problem, you need to call a professional pest control company ASAP.

We recommend calling Terminix or Orkin for conquering your bed bug issues.


Terminix’s customized bed bug treatments start with an extensive inspection of your house. A technician will remove visible bed bugs and use treatments to eradicate hidden bugs and eggs.  The bed bug control is backed by the Bed Bug Guarantee. If any bed bugs are found in the treated room or areas within the next 30 days, the technician will come back for more treatments at no extra cost. If you buy mattress encasements for all mattresses and box springs in your home, Terminix will extend the guarantee to 90 days.

You can reach Terminix at 866-569-4035, or at this form.


The Orkin bed bug treatments involve a variety of treatment options through its Assess, Implement, Monitor system, including conventional treatments with pesticides and heat treatments. Whole room heat treatments require specially designed equipment that raises your home’s temperature high and for long enough to kill bed bugs.

If you’d like a free quote from Orkin, call 877-868-1416 or fill out this simple form.

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