shrew

Shrews are small, mouse-like mammals in the family Soricidae, within the order Eulipotyphla. They are not rodents, though they resemble small mice in size. There are about 385 living species, classified into several genera such as Sorex, Crocidura, and Blarina. Shrews occur in a wide range of habitats, from forests and grasslands to wetlands and urban areas, and are found on most continents except Australia and Antarctica and many isolated islands.

Most shrews are insectivorous, feeding on insects, worms, and other invertebrates, though some will eat plant matter or small vertebrates. They hunt by scent and tactile cues, using their elongated snouts and highly sensitive whiskers. Shrews have very high metabolic rates and must eat frequently, sometimes every few hours, to sustain their energy needs. In several species, the saliva is venomous and helps subdue prey, though bites to humans are rare and typically not dangerous.

Physically, shrews are small with slender bodies, short limbs, and long snouts. They usually have tiny eyes and ears and dense fur. Their sharp incisors have iron-rich enamel that gives them a dark, sometimes reddish, tip. Some shrews are semi-aquatic, like the water shrews, and have adaptations for foraging along streams and in wetlands.

Reproduction varies by species but most breed in spring or year-round in warm regions, producing litters typically of several young. Juveniles develop quickly and mature within a year in many species. Shrews face predation by birds of prey, small carnivores, and larger mammals, but they play important roles in controlling soil and leaf-litter invertebrate populations and are integral to many ecosystems.