The German cockroach is hardly more common in Germany than anywhere else in the world. It lives in the wild in tropical forests. As a synanthrope species in colder regions it favours especially indoor environments that are both warm and humid. Outside the tropical forests the German cockroach lives in bakeries, greenhouses, hospitals etc. It spreads between houses by heat ducts.
The forest cockroach tolerates lower temperatures than the German cockroach. It lives in forests around the world, including Northern Europe, and appears only occasionally inside. In Northern Sweden it is synanthrope.