The genus Cryptotis is a group of relatively small shrews with short ears, which are usually not visible, and short tails, commonly called small-eared shrews. They have 30 teeth and are members of the red-toothed shrew subfamily. Since 1992, Neal Woodman (in cooperation with Robert Timm) at the United States National Museum has been in the process of revising the genus. To date, this has resulted in an increase in the number of species from 12 to 30.
Members of the genus are found mainly in Central America; the North American least shrew, C. parva, is the only species found north of Mexico. The genus occurs as far south as northern Peru and as far east as western Venezuela in South America. It is the only soricomorph genus found south of Guatemala. The limited diversity and restricted northern distribution of shrews in South America implies that the group invaded the continent relatively recently from Central America, where they are more diverse, presumably as part of the Great American Interchange. However, shrews have no fossil record in South America that would allow their arrival to be dated.