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What are the Differences Between Bed Bug Bites and Flea Bites?

When my 9 year old daughter mentioned that her mosquito bite was itching quite a bit, I was immediately intrigued (and admittedly slightly concerned). A mosquito bite is not inherently concerning in Detroit, but a mosquito bite in November…with a foot of snow on the ground, now that is something to raise some eyebrows. She had chosen a mosquito bite because of the availability heuristic (more on this later), and I immediately started down other mental avenues. 1st up – other common insect bites (ones that are still around in the winter). What are the differences between bed bug bites and flea bites?

Availability Heuristic

The availability heuristic is an interesting mental device that can sometimes help, but oftentimes hinder the diagnosis of bites, rashes, bumps, lesions, etc. that appear. The availability heuristic is a mental evolutionary device that pushes our brain to associate results with most known and imaginable causes. For my daughter, this bite was similar to mosquito bites. Since she had some mosquito bites a month or two ago, so it is easy to imagine the same thing happening.

For me, this was a silly possibility unless we are talking snow mosquitoes, but this is not as easy to imagine as she went to a friend’s house and had a flea or bed bug encounter. For the rest of us here in Detroit, our brain will go to what seems most likely to us. This may be influenced by an experience a friend or family member had or possibly even whatever Google search throws at us. It is important to not get too hung up on what immediately comes to mind but to work through it logically.

image of a cockroach

Location I

The most important piece when identifying a bite is to consider the location of the person when they received the bite. Bed bugs are quite cautious and stealthy. They like to hang out in places where they can sneak out and feed without having to travel more than a few inches and then slip back into hiding. This usually means the bite is likely to occur in a place where the person is at rest for long periods of time such as a couch or in bed.

For fleas, the location is typically going to be tied to somewhere that pets frequent. Carpeting and upholstery are the most likely type of area for fleas to hang out especially if that is near the pet’s resting areas. That being said, fleas can do just fine on hardwood floors. Not having a pet in the vicinity also does not rule out fleas as they can find their way in after riding around on a mouse or a squirrel, but a pet makes it much easier for them to thrive. Finally, don’t forget about neighbor pets. Sometimes we forget how much our neighbors can influence our lives.

Location II

The second type of location to consider when investigating the differences between bed bug bites and flea bites is the location of the bites. Flea bites are quite often on the ankles or lower legs around sock or pant lines. This can also be true of other clothing lines around the waist, arms or neck. Fleas like to hop and bounce extreme distances and are likely to latch on to clothing, then bite the first skin they contact.

Bed bugs are simply going to bite the easiest point to access a person at rest. This can be the neck, back, side, arms, legs, etc. In some cases, the bites will even end up being in a linear fashion. This is more likely to occur when a part of the body is lined up with an easy hiding point where multiple bugs can sneak out, feed and head right back into hiding. They don’t need to crawl and jump around, they just go to the closest blood scent.


Reactions to bites of either fleas or bed bugs can range from severe to non-existent. Different people react differently to their bites. In fact, the same person may react differently from one episode to the next depending on a lot of other variables.

We have had countless discussions with couples who have very differing opinions of what occurred when based on the fact that one of them has reactions and the other does not. It is hard for the non-reactor to imagine anything biting them while it is hard for the reactor to think of anything else (see availability heuristic above).

Visible Characteristics

Flea bites usually look like small red dots. They often appear in a few clusters. In some cases they may have a slight halo (not to be confused with the Lyme halo). They are most commonly seen on feet ankles, lower legs, etc. They tend to be more prevalent on clothing lines where access is easiest.

Bed bug bites also tend to be grouped together (though not always the case). Rather than being clustered, they tend to be more linear or zig-zagged in pattern. They can be small or large reactions, flat or raised, etc.


In many instances, tracking patterns is the key to identifying the cause of a dermal reaction. Things to keep track of may include:

image of a tick

  • time of day
  • length of time bites stay visible
  • locations where bites occur
  • locations on the person where the bites appear
  • changes of weather (changes in humidity can affect reactions for example)
  • changes of soaps or detergents (sometimes skin reactions can occur from factors other than bugs)
  • changes in size, shape, or severity of reactions

Seeking Help

It is important to be patient and gather good information. Once you know there is a persistent situation, it is important to seek advice both from a medical professional and a pest control specialist. In both instances, the professionals will gather evidence and make an educated conclusion. Both will be focused on different things and will have access to different information. By combining the two efforts and not simply going with the most convenient answer, you will be most likely to find the verdict. With all biting insect questions, the biting insect specialists at Rove Pest Control are ready and willing to help.