Its habitat varies; in Patagonia it inhabits arid bushy steppes; further north it is found in the forests of Nothofagus, Saxegothaea and bamboo; elsewhere it occurs in tussocky grassland, marshes and wet meadows.

In grassy habitats, it creates runways and makes a nest of grasses in a tussock, among roots or under a rock.

It can climb and also dig, and in Chile it sometimes occupies burrows made by other mammals such as the coruro (Spalacopus cyanus).

The enormous quantities of seeds were followed by a mass population increase of the rice rat Oligoryzomys longicaudatus and to a lesser extent, of the olive grass mouse.

Increases in rodent numbers can be attributed to a greater fecundity, a higher survival rate of juveniles and an extension in the breeding season.