The most noticeable difference is their size and the absence or length of wings. The German cockroach is by far the most likely species to infest homes in this state. The adults are fully winged but rarely fly. The nymphs resemble the adults but are smaller, darker and wingless. Adults live an average of 20 weeks.
Egg capsules remain attached to the female until the eggs start to hatch.
The female produces seven egg capsules. Each capsule can contain up to 48 eggs, more eggs per case than other species. Thus, one female can generate up to 35,000 offspring per year. This explains why large numbers of cockroaches sometimes seem to appear overnight. German cockroaches prefer kitchen and bathroom areas but will disperse to other rooms as their numbers increase.