The female cockroach produces up to eight purse-like egg cases at monthly intervals. The egg cases are thick walled and are 6-12mm in length and may contain up to 30 eggs. The young or nymphs of the German Cockroach emerge from their eggs in 2-4 weeks and those of the Oriental Cockroach in 6-12 weeks. The nymphs are similar in appearance to the adult but smaller. As the nymph develops it grows and moults. This usually occurs 5-10 times during its development which may take up to two years to complete until the insect reaches maturity. The life cycle is complete in a further four months for Oriental Cockroaches and nine months for the German Cockroach

Cockroaches have been pests in mans dwellings for centuries and are always difficult to eradicate, largely because of their secretive and nocturnal habits. They may be found wherever there is a supply of food, water and warmth ie kitchens, housing, bakeries and food factories. They can carry disease organisms particularly those causing food poisoning.

Cockroaches carry food poisoning germs on their bodies and are responsible for the spread of dysentery and gastro-enteritis. They will feed on almost anything including faecal matter and food for human consumption. Contamination will occur when the insect comes into contact with food or work surfaces or through faecal contamination of foodstuffs.