Updated: April 7, 2022

Bed bugs; they’re nasty, they’re dirty, they’re creepy, they’re crawly but did you know that their waste can tell you a lot about what kinds of bed bugs you’re dealing with? Bed bug poop can appear as brown, red, and even black depending on the location and age of the droppings. 

Aside from destroying your mattress, there are some surprising health side effects too. 

If you’re worried about bed bug poop, you’ve come to the right place. Here are 5 things you need to know about these extremely troublesome creatures. 

How Do You Identify Bed Bug Poop?

If you’re looking for a sure-fire way to determine if you have bed bugs, look for their feces. Identifying their poop is a definitive answer to your horrifying question. The nastiest part about this is that bed bugs poop when they walk. 

Look for Patterns

It’s gross, but know that droppings will fall in some sort of pattern or line. If you have a large infestation there will be multiple tracks of these lines throughout your mattress. You will not see individual pellets, like you may expect. Their feces will appear in a streak that is usually flat. 

Black Dots

You can also find black dots of feces on the sides of your mattress. It can resemble mold or even putrid polka dots. If the feces hasn’t absorbed into the fabric of your mattress, small droplets can appear. They’re typically the size of ink spots or a drop of water if you were to spill it. 

The Smell

Bed bug poop doesn’t smell like the feces of a dog or a cat. It actually smells like rust, which makes sense because they’re essentially full of your blood and blood smells like rust. 

Through the transitive property of grossness, bed bug poop smells like blood. 

Even more specifically, once the bed bugs have set up camp in your mattress, they will collectively give off the smell of coriander or musty linen. If you know your sheets are freshly laundered and weren’t left in the washer for too long and you smell that mildew…you may have bed bugs. 

Sorry for the bad news! 

Does Bed Bug Poop Smear?

Unfortunately, the answer to this question is yes. Fresh feces look like small droplets that are extremely smearable. This is when you’ll get it on your sheets.

(We’ll talk about that disgusting part later.) 

The tricky part is that if you only have a few bed bugs lurking around you may mistake the droppings for dirt or food stains.

Rusty and Brown or Black

If you can’t tell if you have a random brown spot on your mattress or if it’s bed bug feces, try wiping the spot with a wet paper towel. If it smears it’s poop. If you’re still not sure, the black mark will turn a rusty red color when it’s smeared. Weirdly enough, that red color won’t show up on your bed. It’ll be on the towel you use. 

Why is it red? 

It’s because they have been feasting on your blood! 

Can I wipe it off?

Unfortunately, you can’t wipe away the smears of bed bug droppings. When the feces dries or gets older than a few hours, it will stain like regular animal feces. You will need to clean the mattress industrially or most likely, throw it out if there is any evidence of bed bugs. 

Alternatively if you need a quick fix, you can use a damp cloth with dish soap, place it on the stain and let it sit. Baking soda and disinfectant spray can also go a long way to make the mattress feel cleaner. 

What About My Sheets?

Typically, for better or for worse, you can’t tell if you have bed bugs by simply looking at your sheets. Bed bugs typically burrow inside of your mattress so you can mostly see them on the corners and sides of your bed. 

Blood Suckers

Bed bugs take a while to bite you, get your blood, digest it, and then drop it. By the time they’ve come up to the surface to feed, they’re well below your sheets and back into the mattress. Bed bugs are also extremely easy to crush after they’ve fed. Their stomach expands and becomes more viscous, causing swelling in their bodies. 

If you crush a bed bug that’s full of blood, clearly it’ll leave a stain on your sheets. 

Searching for Bed Bugs

Check the head and foot of the bed too. Even more disturbing, you’ll even see little eggs where the bed bugs have nested. The best way to identify these eggs is to look at your bedside. The bugs like to borough so you won’t often find traces of them on your sheets. 

If you use a mattress protector, evidence of their feces may end up on the underside of it. If you do find evidence on your sheets it’ll be in the trail of feces they leave..

(Which you now know looks like smearing or streaking).

What if it’s not bed bug droppings?

If you just see black spots on your sheets, it might not be bed bugs at all. It could be mold or even burn marks from washing your sheets on too hot of a setting. 

What About My Health? Does Bed Bug Poop Hurt Me? 

Any kind of feces from an animal or bug in close proximity to you can have a negative effect. They can actually make you experience a variety of health issues. These things literally suck blood and create reactions similar to mosquito bites at the site where they dive in. 

Most of the reactions are skin based, causing swelling, however; you can contract much more dangerous infections and symptoms like the ones listed below. 

According to the Environmental Protection Agency Bed Bugs Can Cause: 

Allergy symptoms due to bites. 

  • Red marks – these will be similar to bug bites
  • Itching – again, like mosquitos you can expect itching and swelling 
  • Anaphylaxis (severe bodily reaction) – anaphylactic shock can be deadly. If you are experiencing any of the following, visit an emergency room as soon as humanly possible.
  • Drop-in blood pressure
  • Trouble breathing / closing of airways 
  • Skin rash 
  • Nausea
  • Vomiting
  • Rapid weak pulse
  • To treat anaphylaxis, you must have a shot of epinephrine. If you do not have severe allergies, you will not have this on hand. Go to the ER! 

Secondary skin infections

  • Ecthyma – This nasty skin condition manifests itself in inflamed sores on the body. This can be brought on by contact with bed bug feces, as the condition often afflicts those with poor hygiene. If you don’t know you have bed bugs, this can easily trigger the infection.
  • Lymphangitis – Your immune system is attacked by this infection. You may experience swolen lymph nodes in the throat or armpits accompanied by painful swelling. If you have these symptoms and are not diagnosed with the common causes like diabetes, it may be related to bed bugs. 
  • Impetigo– This condition is mostly related to heat and friction. If you’re rolling around with bed bugs and their feces, you’ll create friction on your skin. As gross as that sounds this condition features red sores and general redness around places like the mouth. Ugh. If this is happening visit a dermatologist or your GP.

Mental health impacts

  • Anxiety – Who wouldn’t be anxious? Let’s be real. 
  • Paranoia – Many bed bug victims suffer from prolonged paranoia and even phantom itching because they feel like they still have the bugs even after extermination. 
  • Insomnia – If you’re itching and scratching and uncomfortable in bed your sleep will definitely be affected. Also, just the thought of bed bugs can make a person avoid sleeping.

What if There Are Droppings But You Can Find The Bed Bugs?

Bed bugs are sneaky. They can go months without being detected, which leads to large infestations. You may not feel an itch, see droppings, or locate the bugs through visual means. 

Professionals advise that you check the following places if you can’t immediately see the bugs, but have found feces: 

  • Under plastic bed corners
  • Box spring
  • Where box spring is stapled to its frame
  • Mattress piping
  • Visual inspection of the bottom of your mattress
  • Remove the mattress and check under bed frame

Bed bugs are a nuisance, a health risk, and a property destroyer. We hope that these tips help with your questions about bed bug poop, and of course getting rid of them.

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Date Published: 2021-05-14

Written By Robert Brown

I'm a seasoned pest control veteran. I focus my time on writing educational content about the industry and helping people learn about indoor insects. When I'm not thinking about bed bugs I am spending time with my daughters or walking the dog.

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