What Does Cockroach Poop Look Like? (Identifying Roach Droppings)

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Updated on January 6, 2023

Of all the bugs out there that you pray will never enter your home, one of the worst is the risk of roaches. These critters are the source of a common phobia, and for good reason. These little nasties can do a lot of damage to your home, spread a whole host of diseases, and can even bite!

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So what happens if you’re in the kitchen one day and spot a cockroach? Or even worse (since roaches are very good at hiding), spot what appears to be poop? Even in the best of times, poop isn’t a fun topic, but spotting insect poop (called frass) in the house can often be your first indication of an infestation.

So let’s take a few moments to get up close and personal (preferably via a magnifying glass) with cockroach droppings to examine what it looks like, where it can be found, and why you should be concerned if you see it.

Identifying Cockroach Poop

As mentioned already, the presence of frass can often be the first indication of an infestation. This is especially true of many (but not all) roaches, as they tend to skitter for cover at the first hint of light.

But just what do the droppings look like, and how do you know a cockroach made it?

What Does Cockroach Frass Look Like?

cockroach poop

There’s some minor differences in the frass between different roaches that are more than one inch long and those that are smaller. Roaches, like many other insects, don’t urinate separately, which can mean their frass can be solid or mushy.

Large Cockroach Frass

Larger species, such as the American cockroach, Oriental cockroach, and smoky brown cockroach have solid, cylindrical frass. These droppings can be as large as a grain of rice. They have ridges along their length, much like fennel seeds.

Small Cockroach Frass

roach droppings

The brown-banded cockroach, German cockroach, and wood roach are all examples of cockroaches smaller than one inch long. These species have frass that’s a lot different than that of the larger roaches.

They can be hard and look like grains of coffee or poppy seeds. However, the frass can also look like black smears or stains when more liquid is present. The more a roach prefers damp environments, the more liquidy their frass will be.

A Note on Nymphs

Cockroach nymphs produce smaller frass than adults, but the shapes and consistencies are otherwise identical. Because nymphs can be a lot smaller than adults of the same species, their frass is sometimes so small you won’t even spot it unless specifically looking for it.

This can result in contamination risks (which we’ll discuss later on) if your aren’t focused on keeping things clean.

What Does Cockroach Frass Smell Like?

Cockroach frass has an acidic, oily smell that’s hard to miss. This odor isn’t just poop, however. Cockroaches leave pheromones in their frass as signals to other cockroaches.

This means that the traces of poop you found double as little signposts welcoming more roaches to the party.

Roach Frass vs Mouse Droppings

mouse droppings
Mouse droppings

Both mouse (and rat) droppings and the frass of large cockroaches look very similar. However, there are some key differences.

For example, mouse droppings are slightly larger and are smooth instead of ridged. Additionally, roach frass will have blunt ends whereas mouse droppings will have tapered ends. It’s rare, but mouse droppings may occasionally have hairs stuck to them, creating another way to tell the two apart.

Where Is Cockroach Poop Found?

You’ll most often find roach frass near the places those roaches are hiding or nesting. However, it’s also possible to find the frass just about anywhere a roach has been including popular areas of the kitchen such as in the dishwasher, refrigerator, and even microwave.

This is simply due to the fact that cockroaches use their droppings for communication.

Read Also: 17 Different Roaches Found in California

Confirming It’s Actually Cockroach Poop

This is where that magnifying glass comes in handy. Get close to the frass and use the magnifying glass to examine it. You can also take a cotton swab to poke at it (removing the cotton from the poking end can also be useful).

If the frass is loose and has a bit of liquid around it, it could very well be from a small roach. Meanwhile, if you see the blunt ends and ridges, it’s almost certainly frass from a large roach.

The stench will be yet another confirmation that you’re dealing with roaches (although not proof on its own).

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Common Concerns Regarding Cockroach Frass

many cockroaches

Let’s face it, there are a lot of questions that come to mind when one sees signs of an infestation. In fact, we could probably write a book out of such questions.

However, there are a few that are of particular concern when it comes to cockroach frass that need to be addressed.

Does the Presence of Cockroach Frass Mean an Infestation?

Usually, spotting feces is a sure sign of an ongoing or new infestation. However, this isn’t always the case with roaches.

Many species dislike the indoor life and will only wander in seeking shelter during the winter only to vacate your home once the weather gets warm. In other cases, the roach infestation may have been eliminated already, leaving behind some frass that could be several years old if it was never discovered and cleaned.

This is often the case when a house is sold and the owners had to do a quick extermination for it to pass inspection and be put up on the market.

To verify whether or not there’s an active infestation, simply clean up the frass and wait a few days. If no new frass appears, you’re good to go. However, if more turns up, you know you have roaches in your home.

Is Cockroach Frass Harmful to Humans?

Unfortunately, cockroach poop can be dangerous even if you don’t make direct contact. This is one of the reasons a cockroach infestation is so serious.

The frass may be accompanied by body parts or bits of shed exoskeleton as well, which can add to the health risks. Here are the three main ways in which cockroach frass can be dangerous to people.

Cockroach Diseases

The single biggest problem with cockroaches is the fact that they’re major disease vectors. The American cockroach, for example, is known to carry up to 22 different pathogens and even parasites. The rather extensive list includes:

  • Campylobacteriosis (Campylobacter spp.)
  • Cholera (Vibrio cholerae)
  • Dysentery
  • E. coli (Escherichia coli)
  • Gastroenteritis
  • Leprosy (Mycobacterium leprae)
  • Listeriosis (Listeria monocytogenes)
  • Plague (Yersinia pestis)
  • Salmonellosis (Salmonella spp.)
  • Staphylococcus (Staphylococcus aureus)
  • Streptococcus
  • Tapeworms
  • Typhoid fever (Salmonella typhi)

Note that while some of these ailments produce relatively mild symptoms, others can be life-threatening and can led to permanent side effects or even death (the most permanent side effect of all).

Cross Contamination

Adding onto the disease issue is the very real problem of contamination and cross contamination. Cockroaches love going after any scraps of food you have laying around and will try to get into packaged goods as well as sneaking a taste of that food you were preparing when the doorbell rang.

Not only does this mean you could be eating their poop without realizing it, but there’s also a possibility the cockroach picked up a contaminant from somewhere else and brought it to your food.

Frass is Also an Allergen

Finally, the frass can be a major allergen for some people. There are proteins in the frass that can continue to contaminate surfaces long after the frass itself has broken down. Allergic reactions can range from mild to severe.

Asthma attacks can be set off by the frass as well, which affects the air quality around it. But even worse, the presence of cockroach frass has been found to be an actual factor that can lead to children developing asthma. Thus, the health problems roach poop causes can be lifelong.

See Also: Are Cockroaches and Shrimp Related?

Is Cockroach Frass Harmful to Pets?

dog on couch

While many of the diseases cockroaches carry aren’t harmful to your pets, they can still make your pet sick. Air quality is once again a concern, but there is also the issue of pathogens that your pet can contract.

Parasites are another very real problem, as these can easily infest your pet and have more visible side effects than in humans.

Dealing With Cockroach Poop

So now, we’ve established that cockroach frass is a rather dangerous substance that ought to have its own version of a radioactive symbol on it. On top of that, the danger doesn’t go away just because the poop is no longer visible.

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So how do you deal with such a scary thing? Believe it or not, a good deep clean will take care of the problem without you having to abandon your home.

Perhaps down the road we’ll do a more detailed explanation of how to clean up frass (including cockroach frass), but for now, here’s a basic overview of the steps:

  1. Wear gloves and a face mask.
  2. Vacuum using a HEPA filter.
  3. Use a quality carpet shampoo, following the package instructions.
  4. Use disinfectant sprays on smooth surfaces such as counters and walls.
  5. Treat any fabrics (including your mattress) with disinfectants and wash clean.
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