[4] A study of mitochondrial DNA across the species' range published in 2016 solidified Octodontomys as a monophyletic group, albeit one with two distinct lineages, one of which is distributed across Bolivia and northern Chile, the other restricted to Argentina.

The only species of octodontid found in the higher parts of its range, it inhabits dry rocky areas with tall cacti, shrubs and herbs.

It is a sociable animal and communicates by means of a range of low, medium and high-pitched gurgles, twitters and squeaks,[6] similar to the common degu and various species in genus Cavia.

[9] Social groups of the mountain degu range from 2 to 4 individuals that share a burrow system together to rest and hide from predators.

[10] The mountain degu feeds on the leaves and bark of shrubs, and on Acacia sheaths in the winter and on cactus fruits in the summer.

[11] O. gliroides is listed as being of "least concern" by the International Union for Conservation of Nature because of its wide distribution, its presumed large population, its occurrence in some protected areas and apparent tolerance of some degree of habitat modification.