The Colombian grass mouse is a small rodent of the western Colombian Andes. It has been recorded in cloud forest and nearby modified habitats, and it lives on the ground, active by day and at twilight.
Its upperparts are dark olive-brown and its underside is dark gray-brown. Its tail is shorter than its head-and-body length and nearly hairless.
It is terrestrial and mostly diurnal and crepuscular. The account provides no information on diet or breeding.
An extinction-risk assessment has not been added yet.