There are records of tree climbing by Blarina and Sorex. Most forms travel at a swift run. Some experiments with the oxygen consumption of shrews have demonstrated a higher metabolic rate at rest than for various wild mice and voles of the same weight. Other experiments, however, indicate that shrews have a metabolic rate comparable to that of other mammals of the same size. It has been suggested that the high rates of oxygen consumption exhibited by the shrews in the former group of experiments are due to external factors such as nervous stimulation rather than to higher inherent rates of tissue metabolism.
Shrews are generally solitary except when they pair off during the breeding season.
One exception is Cryptotis parva, a species that is somewhat gregarious and colonial. Shrew populations vary greatly with the seasons of the year. The members of this family live under litter or beneath the surface of the ground in runways they construct or in those dug by mice and other small burrowing animals. Shrews may employ echolocation. Shrews are mainly insectivorous and carnivorous, but some eat seeds, nut meats, and probably other plant material.