There are three species of rat in New Zealand.
Rattus rattus common names: ship rat, bush rat, roof rat, black rat, is the most widespread found in towns, cities, farms, scrub and forests.
Rattus norvegius common names: Norway rat, brown rat, water rat, sewer rat, is heavier and larger and is found in wet areas rivers, streams, lakes, sewers, farms and rubbish dumps.
Rattus exulans common names: kiore, Polynesian or native rat is the smallest of the three and is confined to various islands and Fiordland.
Poison baits are the most effective form of rat control. Bait can be purchased from garden centres or hardware stores. Follow the instructions on the packet. Handle with disposable gloves and wash hands thoroughly afterwards. Keep pets and children out of danger by securing the bait with wire inside a piece of drainage pipe or plastic container with 75mm holes in each end. Leave and replenish the bait for at least two weeks after the feeding activity has finished.
Rats tend to avoid traps and are not so effective.
Traps work well for catching mice. Set several together and ensure the bait is firmly attached. Poison bait can be used, place a number of bait stations together where mice activity is observed. This will ensure they eat enough as they tend to nibble a little of each bait.