There are three types of rat in New Zealand. The Pacific rat or kiore (Rattus exulans), the Norway rat (Rattus norvegicus), also known as the brown rat or water rat, and the ship rat (Rattus rattus), also known as the black rat or roof rat.
The kiore came in waka with the first Polynesians about 750 years ago and feasted on the undisturbed birds, insects and lizards. Kiore are now found only in Fiordland, Stewart Island and some off-shore islands. They have been displaced from the mainland by the larger and more aggressive European rats.