In 2003 researcher Lisa Matisoo-Smith began DNA tests on mummified rats found preserved in Pompallier House, one of New Zealand’s oldest buildings. She was interested in what the rats’ DNA could tell her about their origins. In her earlier work examining the DNA of Pacific rats, she concluded that rats found in New Zealand are most closely related genetically to Pacific rats found in the Cook Islands and Tahiti. As rats could only have arrived in New Zealand with the help of humans, this research provides one of the strands of evidence that the Polynesian ancestors of Māori settled New Zealand from East Polynesia.