They are nocturnal creatures that are generally only seen during the day if there is a high population.
There are many species of cockroaches, a few of the most common ones are the German, American, Australian, Brownbanded, Oriental and Smokybrown. These cockroaches can be found in Australia and can carry diseases such Salmonella and Gastroenteritis. Cockroaches can be found in the kitchen, roof voids, subfloor voids, warehouses, food stores, bakeries, restaurants, hospitals, factories, garages, sheds, around drains and under leaf or bark litter outside.
Cockroaches exploit the environment for food and shelter. Many kitchen environments can provide all year-round warmth, food and shelter which may support literally thousands of cockroaches. Cockroaches contaminate foods and food preparation areas with droppings, casts skins, empty egg cases, dead cockroaches, vomit and odours caused by abdominal secretions. Infestations of cockroaches are generally regarded as a threat to human health.