Cockroaches could be considered as one of the worst household pests, because they contaminate food with their excrement, produce allergens and secrete an unpleasant odour. Many people develop allergies to cockroaches. Cockroaches prefer moist, warm, dark places typical of many homes.
Cockroaches will eat almost anything they find, including pet food, crumbs, spoiled food, paints, wallpaper pastes, and book bindings. They can carry germs from the sink or bathroom onto dishes and other food surfaces, thus spreading bacteria that cause food poisoning.