This bat ranges along the Andean highlands and the Mérida range in Venezuela. A 2022 revision separated related specimens from western Ecuador's lowlands as the new species M. moratellii.
Its long, woolly back fur has dark roots and tips ranging from brown to cinnamon and ochre-tawny. Dense fur covers the legs and the upper side of the tail membrane, reaching the knees.
The paper associates M. keaysi with Andean highlands and records it in dense evergreen forest, montane cloud forest, and higher seasonal forest with shrubs and sparse trees.
An extinction-risk assessment has not been added yet.