The crafty vesper mouse is a small rodent recorded in Argentine grasslands and grassy areas of western Brazil. Natural-history information is limited; in northeastern Argentina it appears to favor tall grass on ground that is not flooded.
The back is grizzled gray, the flanks buff, and the underside pale gray. The ears are relatively large, and the slender tail is darker above than below.
Natural history is poorly known. In the Mesopotamian region of Argentina, the account says it seems to prefer tall grass on non-flooded ground.
An extinction-risk assessment has not been added yet.