Most species of rats and mice prefer to live and nest outdoors. Norway rats are burrowers that will build nests in vegetation, along patios, and more. Roof rats are known to nest in trees and on rooflines. Deer mice have a wide range of habitats, often in open fields, forests, or even deserts. Rodent nests can be found in many places, including beneath decks, in tree cavities, under rocks or stumps, and more.