They had some experience in this area, because New Zealand is an island nation with no native land mammals whatsoever. Sheep, mice, cats, stoats, hedgehogs, deer—they all arrived with humans in the last few hundred years. That means the Department of Conservation (DOC) has had to figure out effective ways to get rid of mammalian predators before. They had previously eradicated mice from some smaller islands near to the mainland, but the Antipodes effort—dubbed the Million Dollar Mouse project—is one of the largest ever attempts to rid an area of mice. Antipodes island is about 2,100 hectares, which is roughly 1.5 times the size of Los Angeles International Airport (that sounds small, but just go on Google Maps and look how huge it is).