The German cockroach is the most common species of cockroach, found all over the world. German cockroaches prefer to live in cracks and crevices near food and moisture sources, hence their affinity for residential and commercial kitchen environments.
German cockroaches are found throughout structures, but they prefer warm, humid places. They are commonly found in kitchens and bathrooms. They are good hitchhikers and often find their way into new structures via grocery bags, cardboard boxes, drink cartons and secondhand appliances.
In addition to being a nuisance, the German cockroach has been implicated in outbreaks of illness and allergic reactions in many people. Cockroaches have been reported to spread at least 33 kinds of bacteria, six kinds of parasitic worms and at least seven other kinds of human pathogens. Medical studies have shown that cockroach allergens cause allergic reactions in children and can exacerbate asthma attacks.