Cockroach poop is fecal matter that is left by cockroaches and is typically black or brown in color. Small cockroaches generally drop black poop that visually resembles black pepper or ground coffee. Larger-sized cockroaches create black or brown poop with ridges on its sides and a cylindrical shape.
Cockroach poop can be hazardous, as it contains allergens and proteins that could trigger an asthma attack. A study by the United States National Institute of Environmental Health Sciences in 2005 proved that the presence of cockroach allergens can worsen asthma symptoms. To minimize allergic reactions from cockroach poop, a homeowner should clean and vacuum areas where it is found with soap and warm water.