Least shrews live south of the Great Lakes across the eastern United States. They also occur through eastern Mexico to northern Nicaragua in Central America. Within this vast area the shrews occupy a variety of habitats. In northern parts of the range, least shrews are found in grasslands, meadows or areas covered in a thick layer of brush. Further south, where it is generally drier, these shrews are more common in the vegetation that grows along the banks of streams and lakes.
This mammal has black fur on its back and white fur on its underside. In summer, the upper fur often pales slightly to brown. The milk teeth of young shrews fall out while the animals are still in the womb.
Least shrews move through the plant cover in tunnels called runways, which connect their nests together. The nests are constructed underground in burrows dug by the shrews, and then lined with leaves. Least shrews will also take over and extend burrows made by other animals. Rather unusually for shrews, this species is relatively social. The nests are shared, and more than 30 shrews have been found living together in a single nest.
Least shrews are almost exclusively flesh eaters. They have been seen to open up the abdomens of insects such as grasshoppers to eat only the most nutritious internal organs.
Distribution: From eastern United States south to northern Nicaragua in Central America.
Habitat: Grass and brush.
Food: Insects, worms, slugs and snails, plus some plant matter.
Size: 5 - 8 cm (2 - 3 in); 4 - 6.5 g (0.1 - 0.2 oz).
Maturity: 5 weeks.
Breeding: Several litters of about 5 young produced in summer.
Life span: 1.5 years.