Cockroach Poop: Identifying Roach Droppings vs. Mouse Droppings (and others)

Written by Brandi Allred
Updated: October 29, 2023
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At one time or another, you’ve probably found a tiny dropping in your home, and wondered: is this cockroach poop, or mouse poop? It’s a reasonable question; both cockroaches and mice are often unwelcome pests in homes and businesses. It’s important to be able to determine whether you have an insect problem or a rodent problem.

Cockroaches are notorious for spreading filth and disease; their presence is often a nightmare for home and business owners. Even if you haven’t seen a roach in your home, finding poop can be a sign of a big problem.

Here, we’ll learn how to tell whether you’re looking at roach droppings, or mouse poop. Then, we’ll cover just how dangerous cockroach poop is, and how to tell if you have an infestation. Then, we’ll go over all the signs of a cockroach problem, and why you might get cockroaches in an otherwise clean home. Finally, we’ll examine how to get rid of cockroaches, and how to prevent them in the first place.

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What Does Cockroach Poop Look Like?

Cockroach Poop - Cockroach next to Feces

Cockroach poop is very small and looks like grains of rice.


Sometimes it can be hard begin cockroach droppings identification. Cockroach poop is very small; under 1 millimeter. Roach poop is also extremely regular, like a grain of rice (though it’s about half the size of a grain of rice). It’s usually dark brown, and seed-like in appearance. From a distance, it may look like specks of dirt, or even like mouse poop.

Smaller cockroaches leave behind smaller poop; it may look like spilled ground coffee or ground black pepper.

Is Cockroach Poop Harmful?

Most cockroaches are not harmful to humans, but there are a few species that invade homes and spread disease and allergens. Cockroach poop, in particular, contains compounds that can trigger allergic reactions, like asthma, in people.

Specifically, breathing air that has been contaminated with cockroach poop, shed exoskeletons, and roach pheromones can cause allergy-like symptoms in people. Additionally, should cockroach poop be ingested, it can cause severe, food poisoning-like symptoms.

Cockroach Poop or Mouse Poop?

Cockroach Poop  vs Mouse Poop
Cockroach poop is smaller and more regular than mouse poop.

Cockroaches leave behind droppings just like any other creature. Like mice and rats, they often infest homes and businesses—to the detriment of owners and tenants. But, how do you tell cockroach poop from mouse poop? Well, your first step is to look at the poop in context; where is it? And, have you seen cockroaches, or mice, around?

The reason the location of the poop is important is that cockroaches can fit their bodies into much smaller spaces than mice. So, if you’ve found the poop in a spot that seems improbable for a mouse, chances are it belongs to a roach. 

The next thing to look at is the size and shape of the poop. Cockroach poop is very uniform and regular, like a tiny grain of rice or a seed. Mouse poop looks more like mammal poop (if you’ve ever seen a dog or cat mess, then you know what mammal poop looks like). Further, mouse poop is bigger than cockroach poop—up to twice as large. Rat poop is even larger, up to the size of a dried bean.

Does Cockroach Poop Mean You Have an Infestation?

Unfortunately, the presence of cockroach poop is a sure sign of an infestation. If you’ve noticed roach poop in your home or business, it’s very likely that there are also cockroaches, cockroach nymphs, and egg cases somewhere in the vicinity. 

Other Signs of Roach Infestation

You may think that all roaches want to come into your house and make themselves at home, but that’s simply not the case. Under 30 species of cockroach ever come into contact with humans; that’s less than 1% of the over 4,500 species of roach around the world. For the few species that do make foul-smelling nuisances of themselves, there are a few sure signs of infestation.

First; seeing a cockroach. If you see one cockroach, there are almost certainly more. The presence of cockroach poop, stains, and bad smells is another indication that you’ve got a problem. Finally, baby roaches, egg cases, and shed exoskeletons are all signs of a budding cockroach family.

What Causes Roaches in a Clean House?

You might be asking yourself: but my house is clean, why do I have cockroaches? The answer is that, no matter how strenuously you clean your home—there may be factors beyond your control. Living in a multi-unit housing facility is one; living at the end of a sewage system, or near filthy surroundings, are others.

If you are in one of these situations, the best thing you can do is take every step possible to avoid roach infestations in the first place. 

Types of Cockroaches - German Cockroach

Cockroach poop may look like ground black pepper, ground coffee, or tiny, dark brown grains of rice


How to Get Rid of Roach Poop and Infestation

If you find cockroach poop, your first step should be to clean it up with bleach containing cleaner. Then, you should either call a professional pest exterminator, or buy yourself some glue traps. Glue traps are a good way to identify where the cockroach problem is worst.

From there, you can treat the area with pesticides. Use the utmost caution though when you use pesticides; they’re toxic to both people and pets.

How to Prevent Cockroach Infestation

Once you’ve taken care of the cockroach poop and infestation, you’ll want to cockroach proof your home or business. Start by picking up all garbage, waste, and leftover food—these are all cockroach attractants. Then, clean up. Sweep up any piles of dust (which are mostly made up of shed human skin cells, which roaches love), and take care of any clutter. Ensure that all stored items are kept in plastic totes—not cardboard boxes, roaches love corrugated cardboard. Then, you may want to lay baited traps to catch any stray roaches that try to infiltrate your home or business. 

How Many Types of Cockroaches Are There?

Giant Burrowing Cockroach

The giant burrowing cockroach is considered the heaviest cockroach species in the world, weighing up to 1.23 ounces or 35 grams.


Did the subject of roach poop cause you to pause and wonder how many types of cockroaches there are in the U.S. or worldwide? Believe it or not, there are over 4,500 different types of cockroaches on the planet! Maybe it’s not that surprising, given the jokes surrounding how cockroaches would likely survive a nuclear holocaust or any other type of catastrophe just fine.

In the United States, there are 69 species. Types that seem to be spoken of the most include American cockroaches, German cockroaches, brown-banded cockroaches, smoky brown cockroaches, and Oriental cockroaches (often referred to as waterbugs). Other American varieties are the Pennsylvania wood cockroach, three-lined cockroach, field cockroach, and Florida woods cockroach.

If cockroaches give you the heebie-jeebies, consider the top 5 largest cockroaches in the world:

  • Megaloblatta Longipennis – largest in the world at 3.5 inches long, 1.5 inches wide, and an 8-inch wingspan
  • Giant Burrowing Cockroach – 3.1 inches long, weight of 1.5 ounces
  • Blaberus giganteus
  • Madagascar Hissing Cockroach
  • Death’s Head Cockroach

The photo featured at the top of this post is © IrinaK/

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About the Author

Brandi is a professional writer by day and a fiction writer by night. Her nonfiction work focuses on animals, nature, and conservation. She holds degrees in English and Anthropology, and spends her free time writing horror, scifi, and fantasy stories.

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