Cockroach Feces

Cockroach Droppings: What Does It Look Like?

A telltale sign of a potential infestation, cockroach feces can also indicate the type of species present in the building and give an estimate of the population size of infesting cockroaches.

Seeing the Feces
When cockroaches first enter a home, the cockroach feces may not be noticeable. As the cockroach population grows, the feces will start to become obvious. Homeowners will find feces near the cockroach food source, near their hiding places, and near their water source.

What Does Cockroach Feces Look Like?

Depends on the Species
The particular appearance of cockroach feces generally depends on the size of the insect.

roaches & feces
Roaches amidst fecal smears

Of the cockroach species commonly found in North America, the larger American and Oriental varieties, which can each exceed an inch in length, produce cylindrical feces akin to mouse droppings.

When magnified, American cockroach feces appears rounded and ridged, while the droppings of Oriental cockroaches are slightly tapered at one end.

roaches and feces
American Cockroach & Feces

Image credit: Univ. of Florida Entomology Dept

Smaller than American and Oriental cockroaches, both the German and brown-banded cockroach excrete feces resembling specks of black pepper.

German and brown-banded cockroaches often defecate on the walls close to the spaces they occupy.

To Summarize
Roach feces may appear in the following ways:

  • cylindrical
  • “fly specks” or pepper like
  • as large as mouse droppings

Depends on the Environment

The type of habitat each cockroach species prefers also affects the appearance of fecal matter.  American, German, and Oriental cockroaches tend to live in moist environments and often generate more liquefied feces.

The droppings of brown-banded cockroaches, which frequently inhabit higher and drier places within buildings, are typically firmer and more solid in composition.

Cockroaches defecate continuously when feeding, creating unwelcome accumulations of feces on counters, walls, and floors. In addition to serving as an unsightly nuisance requiring thorough cleanup, cockroach feces can cause health problems for home owners, as the excrement may carry infectious and potentially fatal bacteria and viruses.


Besides being unsightly and unsanitary, cockroach feces can complicate an odor problem. The cockroaches produce pheromones from glands on their bodies. These pheromones add to the odor of cockroach feces that happen when there is an infestation. In some cases, the odor is the most difficult part of an infestation to eliminate.

Problems Caused by Cockroach Droppings

Cockroaches produce feces containing certain proteins that trigger an allergic response in humans. Allergic reactions to cockroach feces are most common in urban areas and among residents with asthma or other respiratory ailments. In addition to harming the respiratory health of humans, the allergens contained in cockroach feces are remarkably durable and long-lasting (allergens can persist in environment up to five years after cockroach removal if sanitation is lacking).

Scientists have found a variety of disease organisms in cockroach feces. The cockroaches pick up the disease organism by walking through a contaminated area. When the cockroach grooms itself, it ingests the disease organism.

In a study, scientists found Salmonella surviving in the cockroach digestive tract for several weeks. Mice that were placed in a jar with a tiny amount of cockroach feces became ill with Salmonella.

Feces vs “Sputum”

Dark stains in corners and on walls confuse many people. They assume that these stains are cockroach feces. These dark stains are actually material that the cockroaches spit up. Scientists call this material sputum.

This behavior helps make cockroach bait an effective control tool. Newly hatched cockroach nymphs can receive a dose of roach bait from eating the feces of adult roaches that were feeding on the roach bait.

Things You Can Do

Cockroach feces that are visible can be sprayed with disinfectant and wiped up. If cockroaches have been hiding in cracks and crevices, a vacuum cleaner will remove the roaches and some of the feces. The disinfectant can be sprayed into the crevices to help get rid of the odor. If there were a lot of roaches, it may be necessary to caulk the cracks and crevices to seal up any lingering odor after the roaches are gone.

Get Rid of a Roach Infestation Yourself