Start by removing food and water sources, sealing cracks around cupboards and pipes, and using cockroach baits or traps according to the label. Avoid spraying insecticide over bait, as this can make the bait less effective, and keep all products away from children and pets. If cockroaches keep returning, are present throughout the home, or you find signs such as droppings and egg cases, a licensed pest controller can identify the species and recommend suitable treatment. Follow their preparation and re-entry instructions, and check the product is registered for household use in Australia.