Oriental Cockroach

( Blatta orientalis )


SIZE: An Oriental cockroach generally ranges from 1 to 2 inches in length, but can seem much larger when the intruder is up close and personal.

The Oriental cockroach is typically dark-brown to reddish-brown in color, though it can also seem to appear as a black cockroach in the dark places where this type of roach is generally found.

BEHAVIOR: In many cases, these large cockroaches find the inside area of buildings to be exactly what they are looking for in a shelter. This is especially true during extreme weather conditions. When very hot, cold, dry, wet or even windy conditions occur outside, these roaches become distressed, and our homes and buildings, unfortunately, often provide the comfort they are looking for.

They have no distinctive markings other than the disproportionately small size of their wings, which is the easiest way to identify them. The male’s wings only cover a little over half of the abdomen, failing to reach the tip. Males generally don’t fly, but may be able to fly just enough to avoid danger, if the need arises. On the other hand, the female adult Oriental cockroach cannot fly at all. In fact, her wings are so small that they are barely visible, almost appearing as if they were attached to the wrong insect.


Many people call Oriental cockroaches “water bugs” because they like very damp areas. (They might also be referred to as a ‟black cockroach.”) One of the most likely indoor areas you’ll find Oriental cockroaches is in the basement, especially around sump pumps and water collection systems.

Condensation in walls or around air ducts may also create the damp environment they prefer. Plumbing leaks that are not promptly repaired, damp crawl spaces and any other areas in and around your home with a constant supply of moisture are also all very attractive to Oriental cockroaches.

Likewise, Oriental cockroaches also require very wet areas when living outdoors. They are commonly found in storm and sanitary sewers, heavy vegetation, tree holes that collect water, under mulch beds and other similar areas.

Tips for Control

When the Oriental cockroach infestation is located, there are a variety of control measures which are routinely used by professionals. Insecticide baits, dusts, aerosols as well as liquid treatments are all valuable tools that are very effective when used properly. More than one of these formulations is usually required for effective control of Oriental cockroaches.

  • It’s imperative that dampness be reduced when Oriental cockroaches are infesting a structure.

  • This usually involves fixing leaks, properly ventilating areas or locating other issues that result in trapped moisture inside the structure.

  • Eliminate potential harborages outside of the home.

  • Seal cracks in the outer walls and install screens on vents that lead indoors.