A shrew is any of over 350 species of small insectivores in the family Soricidae. Shrews have cylindrical bodies, short limbs, clawed digits, and a mobile snout covered with sensitive whiskers. They emit different sounds for defense, courtship, and foraging. Shrews are found in North America, northwestern South America, Africa, Eurasia, and islands east of mainland Asia. They have adapted to environments such as tundra, forests, savannas, grasslands, and deserts. Shrews have a long evolutionary history, with fossils dating to the Middle Eocene Epoch. The 24 genera of shrews are classified into three subfamilies: Crocidurinae, Soricinae, and Myosoricinae.

What kind of animal is a shrew—mammal, bird, reptile, or insect?

A shrew is a small mammal belonging to the family Soricidae, with over 350 species. Shrews possess a mobile snout covered with sensitive whiskers that overhangs their lower lip. As mammals, shrews share several characteristics, including hair, mammary glands, and a diaphragm. Shrews have small eyes, and their ears are rounded and moderately large. Shrews are found in diverse environments across North America, Africa, Eurasia and some island groups of Asia. They primarily consume insects and invertebrates, with some species having toxic saliva to immobilize prey.

Where do shrews usually live?

Shrews can be found across North America, extending to northwestern South America, Africa, Eurasia, and various island groups east of mainland Asia. They have adapted to diverse environments such as tundra, coniferous, deciduous, and tropical forests, as well as savannas, humid and arid grasslands, and even deserts. Short-tailed shrews specifically inhabit areas ranging from southern Canada through the north-central and northeastern United States to eastern Texas and Florida. They require habitats with ample cover and well-drained soil that retains moisture for burrow humidity. White-toothed shrews live in temperate and tropical forests, riverine forests, marshes, temperate steppes and other grasslands, savannas, and semiarid habitats.

Shrews are small, active mammals that maintain high metabolic rates by consuming more than their own weight in food daily. They primarily eat insects and other invertebrates, but they also consume small vertebrates, seeds, and fungi. Some species, such as the North American short-tailed shrews and Old World water shrews, produce toxic saliva to immobilize their prey. Terrestrial shrews use their acute senses of hearing, smell, and touch to find food, while amphibious species rely almost entirely on touch to detect prey underwater.

How does a shrew’s body help it survive in its environment?

Shrews possess several adaptations that aid in their survival. Their mobile snout, covered with sensitive whiskers, helps them detect invertebrates in soil and litter. Shrews have a high metabolism and must consume more than their own weight in food daily. Different lifestyles have resulted in modifications in anatomical details. For instance, African forest musk shrews have long feet and toes and a tail much longer than their body, which allows them to travel in bushes, vines, and small trees. North American short-tailed shrews have minute eyes obscured by fur, very small ears hidden in the fur, long digging claws on the forefeet, and short tails, which allows them to burrow. Some shrews also produce toxic saliva to immobilize prey.

How are shrews different from mice or other small mammals?

Shrews are small insectivores with a specialized anatomy and high metabolism that distinguish them from mice and other small mammals. Key differences: * Snout: Shrews have a mobile snout covered with sensitive whiskers that overhangs their lower lip. * Teeth: Their large incisor teeth act like forceps for grabbing prey. Shrews' teeth are not replaced during their life. * Senses: Shrews have an enhanced sense of smell in comparison to their intelligence and manipulative ability. Terrestrial shrews have acute hearing, smell, and touch. * Metabolism: Shrews have high metabolic rates, consuming more than their own weight in food daily, and can't survive without eating for more than a few hours. * Habitat: Shrews can be found in North America, northwestern South America, Africa, Eurasia, and island groups east of mainland Asia to the Aru Islands on the Australian continental shelf. * Classification: Shrews belong to the family Soricidae and the order Soricimorpha, which falls within the broader group of insectivores.

shrew

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A shrew with brown fur and a pointed snout stands on mossy ground.

An illustration of the extinct mammal Batodonoides vanhouteni, showing a small, shrew-like animal with a pointed snout, large eyes, and a long tail, next to a scale indicating its body length is about 3 centimeters or 1 inch.

At a Glance

shrew summary

shrew

mammal

Also known as: Soricidae, soricid

Written by

Guy Musser

Fact-checked by

Britannica Editors

History

Top Questions

What is a shrew?
A shrew is any of over 350 species of small insectivores in the family Soricidae. Shrews have cylindrical bodies, short limbs, clawed digits, and a mobile snout covered with sensitive whiskers. They emit different sounds for defense, courtship, and foraging.

Shrews are found in North America, northwestern South America, Africa, Eurasia, and islands east of mainland Asia. They have adapted to environments such as tundra, forests, savannas, grasslands, and deserts.

Shrews have a long evolutionary history, with fossils dating to the Middle Eocene Epoch. The 24 genera of shrews are classified into three subfamilies: Crocidurinae, Soricinae, and Myosoricinae.
2 Britannica Sources
1. white-toothed shrew
2. shrew
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What kind of animal is a shrew—mammal, bird, reptile, or insect?
A shrew is a small mammal belonging to the family Soricidae, with over 350 species. Shrews possess a mobile snout covered with sensitive whiskers that overhangs their lower lip.

As mammals, shrews share several characteristics, including hair, mammary glands, and a diaphragm. Shrews have small eyes, and their ears are rounded and moderately large.

Shrews are found in diverse environments across North America, Africa, Eurasia and some island groups of Asia. They primarily consume insects and invertebrates, with some species having toxic saliva to immobilize prey.
3 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
Where do shrews usually live?
Shrews can be found across North America, extending to northwestern South America, Africa, Eurasia, and various island groups east of mainland Asia. They have adapted to diverse environments such as tundra, coniferous, deciduous, and tropical forests, as well as savannas, humid and arid grasslands, and even deserts. Short-tailed shrews specifically inhabit areas ranging from southern Canada through the north-central and northeastern United States to eastern Texas and Florida. They require habitats with ample cover and well-drained soil that retains moisture for burrow humidity. White-toothed shrews live in temperate and tropical forests, riverine forests, marshes, temperate steppes and other grasslands, savannas, and semiarid habitats.
3 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What do shrews eat?
Shrews are small, active mammals that maintain high metabolic rates by consuming more than their own weight in food daily. They primarily eat insects and other invertebrates, but they also consume small vertebrates, seeds, and fungi. Some species, such as the North American short-tailed shrews and Old World water shrews, produce toxic saliva to immobilize their prey. Terrestrial shrews use their acute senses of hearing, smell, and touch to find food, while amphibious species rely almost entirely on touch to detect prey underwater.
2 Britannica Sources
1. shrew rat: Natural history
2. shrew
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
How does a shrew’s body help it survive in its environment?
Shrews possess several adaptations that aid in their survival. Their mobile snout, covered with sensitive whiskers, helps them detect invertebrates in soil and litter. Shrews have a high metabolism and must consume more than their own weight in food daily.

Different lifestyles have resulted in modifications in anatomical details. For instance, African forest musk shrews have long feet and toes and a tail much longer than their body, which allows them to travel in bushes, vines, and small trees. North American short-tailed shrews have minute eyes obscured by fur, very small ears hidden in the fur, long digging claws on the forefeet, and short tails, which allows them to burrow. Some shrews also produce toxic saliva to immobilize prey.
1 Britannica Source
1. shrew
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
How are shrews different from mice or other small mammals?
Shrews are small insectivores with a specialized anatomy and high metabolism that distinguish them from mice and other small mammals.

Key differences:
* Snout: Shrews have a mobile snout covered with sensitive whiskers that overhangs their lower lip.
* Teeth: Their large incisor teeth act like forceps for grabbing prey. Shrews' teeth are not replaced during their life.
* Senses: Shrews have an enhanced sense of smell in comparison to their intelligence and manipulative ability. Terrestrial shrews have acute hearing, smell, and touch.
* Metabolism: Shrews have high metabolic rates, consuming more than their own weight in food daily, and can't survive without eating for more than a few hours.
* Habitat: Shrews can be found in North America, northwestern South America, Africa, Eurasia, and island groups east of mainland Asia to the Aru Islands on the Australian continental shelf.
* Classification: Shrews belong to the family Soricidae and the order Soricimorpha, which falls within the broader group of insectivores.
3 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

shrew, (family Soricidae), any of more than 350 species of insectivores having a mobile snout that is covered with long sensitive whiskers and overhangs the lower lip. Their large incisor teeth are used like forceps to grab prey; the upper pair is hooked, and the lower pair extends forward. Shrews have a foul odour caused by scent glands on the flanks as well as other parts of the body.

Shrews are small mammals with cylindrical bodies, short and slender limbs, and clawed digits. Their eyes are small but are usually visible in the fur, and the ears are rounded and moderately large, except in short-tailed shrews and water shrews. Tail length varies among species, some being much shorter than the body and others appreciably longer. The sexes are not immediately distinguishable, as the testes are retained in the male’s abdominal cavity and do not descend. The brain’s cerebral hemispheres are small, but the olfactory lobes are prominent, which reflects less intelligence and manipulative ability but an enhanced sense of smell. The 26 to 32 white or red-tipped teeth are not replaced during the animal’s life (milk teeth are shed before birth).

Natural history

Most shrews are active all year and by day and night, with regular periods of rest. They eat primarily insects and other invertebrates but also take small vertebrates, seeds, and fungi. North American short-tailed shrews (genus Blarina) and Old World water shrews (genus Neomys) produce toxic saliva for immobilizing prey. Shrews have high metabolic rates and may consume more than their own weight in food daily; they cannot survive for more than a few hours without eating. As a result, shrew life consists largely of a frenetic search for food. Terrestrial shrews have acute senses of hearing, smell, and touch. They probe in litter and soil with their muzzle and dig out any invertebrates detected by smell and by their sensitive whiskers. Large prey is pinned with the front feet but grabbed by the mouth and manipulated with the flexible muzzle, with food being pushed sideways as it is chewed. Amphibious species depend almost entirely on touch to detect prey underwater. Shrews emit clicks, twitters, chirps, squeaks, churls, whistles, barks, and ultrasonic sounds in contexts of alarm, defense, aggression, courtship, interactions between mother and young, and exploration and foraging. Shrews have 2 to 10 blind, hairless young in one or more annual litters; gestation lasts up to 28 days. The mother is attentive and occasionally relocates, carrying the young by the neck or pushing them along to the new nest. When the young are old enough, they may form a chain, each grasping the base of the tail of the one ahead, trailing behind the mother as she escapes from disturbances or relocates. This behaviour is called caravanning.

Shrews are found throughout North America to northwestern South America, Africa, Eurasia, and island groups east of mainland Asia to the Aru Islands on the Australian continental shelf. They have adapted to a wide variety of environments, inhabiting tundra, coniferous, deciduous, and tropical forests, savannas, humid and arid grasslands, and deserts. More than 40 percent of the living species (145 of 325) are indigenous to Africa, with 16 species being recorded from one location in southeastern Central African Republic. The Asian house shrew (Suncus murinus) has been introduced into parts of Arabia, Africa, Madagascar, and some Pacific and Indian Ocean islands.

Form and function

The common Eurasian shrew (Sorex araneus) represents the average size of most species, weighing up to 14 grams (0.5 ounce) and having a body 6 to 8 cm (2 to 3 inches) long and a shorter tail (5 to 6 cm). One of the smallest mammals known is the pygmy white-toothed shrew (Suncus etruscus) of Eurasia and North Africa, weighing between 1.2 and 2.7 grams (0.04 to 1 ounce) and having a body 4 to 5 cm (1.6 to 2 inches) long and a shorter tail (2 to 3 cm [0.8 to 1.2 inches]). Among the largest is the armoured shrew (Scutisorex somereni) of equatorial Africa, which weighs up to 113 grams (about 4 ounces) and has a body 12 to 15 cm (4.7 to 5.9 inches) long and a tail 8 to 10 cm (3.1 to 3.9 inches) long. The short, dense, soft fur of shrews ranges from gray to black, with either slightly paler tones or white on the underparts. Some species of Sorex are tricoloured, having a dark brown back, grayish brown sides, and grayish undersides. The piebald shrew (genus Diplomesodon) is white with gray along the head and back.

Dromedary camels (Camelus dromedarius). Animals, mammals.

Britannica Quiz

Ultimate Animals Quiz

Body form is similar in all shrews, but modifications in anatomical details reflect different lifestyles. For example, most shrews live on the ground, but some tropical species, such as the forest musk shrews (genus Sylvisorex) of Africa and white-toothed shrews (genus Crocidura) of Asia also forage and travel in bushes, vines, and small trees beneath the forest canopy. These species have long feet and toes and a tail much longer than the body.

Other shrews are adapted for burrowing. These are the North American short-tailed shrews (genus Blarina), Kenyan shrews (genus Surdisorex), the Asian mole shrew (Anourosorex squamipes), and Kelaart’s long-clawed shrew (Feroculus feroculus) of Sri Lanka. All have minute eyes obscured by the fur, very small ears also hidden in the fur, long digging claws on the forefeet, and short tails. They construct and forage within subsurface burrows, spending only limited time on the surface.

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Water shrews have especially small eyes (covered with skin in genus Nectogale). These are amphibious species that den on land and forage in water. A bizarre and unexplained specialization is shown by the African Scutisorex somereni. It has additional and enlarged lumbar vertebrae interlocked by numerous bony spines, forming a flexible and very strong backbone. This shrew can support the weight of a person.

shrew

Natural history

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Form and function