This cockroach is by far the most important and usually the most common of the cockroaches. In addition too being nuisance, it has been implicated in outbreaks of illness, the transmission of a variety of pathogenic organisms including at least one parasitic protozoan, and allergic reactions in many people.
They are usually found in kitchens and secondarily in the bathrooms, but infestations often occur in rooms where people eat and drink while watching television. German roach show preference for warm (70° F) and humid places. These cockroaches are most commonly introduced into buildings via paper products or paper packaging such as grocery bags, cardboard boxes, drink cartons, and via secondhand appliances such as refrigerators, televisions, VCRs, microwave, etc.