Although closely related to the American cockroach (Periplaneta americana), the smokybrown cockroach is readily distinguishable from it by its uniformly dark brown–mahogany coloration. Furthermore, unlike the American cockroach, which possess a light-rimmed pattern on its thorax, the smokybrown cockroach’s thorax is dark and shiny.
The smokybrown cockroach may come indoors to look for food and even to live; generally, however, in warm weather, it will move outdoors.
The smokybrown cockroach is very common in Japan, as well as the southern United States and tropical climates; notably, it can be found in Florida, Louisiana, Mississippi, Texas, and other moist Gulf coastal states, and along the southern Mississippi River. The cockroach can also be found in Australia, such as in warmer cities like Sydney and Brisbane.
The smokybrown cockroach prefers warmer climates and is not cold-tolerant. It may, however, be able to survive colder climates by going indoors. In addition to this, it fares well in moist conditions and appears to be particularly prevalent in moist concealed areas. It often lives around the perimeter of buildings.