The first upper incisor is enlarged and has a hook at the end. This tooth also has a cusp projecting ventrally at the base. The first lower incisor is enlarged, and projects forward and slightly upward. The skull is long and narrow, and the sutures fuse early in life. The brain is small, with smooth cerebral hemispheres.
Shrews usually inhabit moist areas.
Notiosorex and Diplomesodon, however, are found in arid regions, though their exact habitats are not definitely known. Because of the small size of shrews, temperature and evaporation may be of more importance in governing the distribution of this group than that of most other mammals. Shrews frequently have markedly restricted habitats. They are mainly terrestrial, but some take to water freely, and others burrow a little. There are records of tree climbing by Blarina and Sorex.