The species is nocturnal and arboreal, and lives in thickets of South American mountain bamboo in the Valdivian temperate forests of the southern Andes,[1] aided by its partially prehensile tail.

[2] The generic name Dromiciops is based on the resemblance of the monito del monte to the eastern pygmy possum (Cercartetus nanus), one of the synonyms of which is Dromicia nana.

The specific name gliroides is a combination of the Latin glis, gliris ("dormouse", more generally "rodent") and Greek oides ("similar to").

Australia's earliest known marsupial is Djarthia, a primitive mouse-like animal that lived in the early Eocene about 55 million years ago (mya).

[5] Dromiciops is thought to have evolved from members of the genus Microbiotherium, known from the early Miocene of South America, with some authors considering the genera indistinguishable.

[10] However, in 2010, analysis of retrotransposon insertion sites in the nuclear DNA of a variety of marsupials, while confirming the placement of the monito del monte in Australidelphia, also clarified that its lineage is the most basal of that superorder.

This conclusion indicates that Australidelphia arose in South America (along with the ancestors of all other living marsupials), and probably reached Australia in a single dispersal event after Microbiotheria split off.

[15] Monitos del monte live in the dense forests of highland Argentina and Chile,[16][17][18][19] mainly in trees, where they construct spherical nests of water-resistant colihue leaves.

They have short and dense fur that is primarily brown-gray with patches of white at their shoulders and back, and their underside is more of a cream or light gray color.

It is largely nocturnal and, depending on the ambient and internal temperature, and on the availability of food, it spends much of the day in a state of torpor.

Such behaviour enables it to survive periods of extreme weather and food shortage, conserving energy instead of foraging to no effect.

[10] A study performed in the temperate forests of southern Argentina showed a mutualistic seed dispersal relationship between D. gliroides and Tristerix corymbosus.

[20][30] T. corymbosus also depends on the survival of this species, because without the seed dispersal agency of the monito del monte, it would not be able to reproduce.