Biology:
The reason that German cockroaches are such successful breeders is they carry the egg case (Ootheca) until 1-2 days within hatching. Each egg case produces between 30-40 eggs and they can produce up to 8 cases a year. Development time from egg to adult varies between 54-215 days depending upon the environment. Adults can live on average 200 days

Habits:
German cockroaches are found throughout structures but have a preference for warm (21C) And humid places. They are usually found in kitchens and bathrooms, but they also occur in the lounge and bedroom etc. Any crack or crevice they will use as harbourage. For young adults (Nymphs) they need a crack of only 1mm adult's needs only 5mm. They feed on almost anything including all kinds of food, and such things as soap, glue and toothpaste. Because of the way they spend their time in the harbourage about 30% of the young nymphs will not be seen during an inspection.

Reasons for Control:
Loss of quality, contamination of goods, allergic reactions in a lot of people, prevention of diseases and to comply with UK legislation.