Adult males and females are slightly less than one and one—half inches long. Body is dark brown, and the pronotum has pale margins and a dark brown interior. Large nymphs are dark brown with pale yellow spots on lateral margins of the thorax and abdomen.
Egg case is blackish brown and contains 24 eggs; hatching occurs in about 40 days. Egg cases are produced at about 10 day intervals, and the total is 20 to 30 in a lifetime. Nymph development is 6 to 12 months.
Female development is about 213 days, and males about 198 days. Adults live about 12 months.
Habits. The Australian cockroach is found outdoors around the perimeter of buildings and indoors in kitchens.
It occupies similar habitats as the American cockroach, but does not occur in underground sewers.