It's found statewide in Pennsylvania. Coloration is cinnamon to brown above, ashy gray below, darker in winter than in summer. Favored habitats are open, dry situations, such as old pastures or meadows, or along woodland edges. Least shrews are scattered in local colonies throughout suitable habitat. More convivial than most other shrews, which tend to be belligerent toward others of their own species, least shrews may nest in groups of a dozen or more, especially in winter.
Least shrews are active at all hours, but mainly at night.
They travel their own or other small mammals' runways and burrows. They eat insects, earthworms, centipedes, millipedes, snails, mollusks, frogs and carrion, and they drink water freely. Least shrews build nests of dried grass or leaves, either underground or beneath logs, stumps or debris. They breed from March through November. Three to six blind, hairless young are born following a gestation period variously reported as 15-23 days.