What is a shrew?

This is not an uncommon question. Many people mistakenly think the shrew is a type of field mouse; others assume it is a kind of mole, and still others a form of squirrel. Perhaps the confusion comes from the fact that shrews are so tiny and quick that it is difficult to get a good look at them in the wild. In fact, the shrew is a tiny mammal of the sorex order, distantly related to the mole, yet distinct from it. Although its resembles a long-nosed mouse because of its elongated snout, the shrew is not a rodent, and is in fact not even related to rodents. Unlike rodents, shrews have very sharp, spike-like teeth. Shrews are very tiny; most shrews are smaller than a mouse.

Common shrews

Michigan is home to several kinds of shrews, such as the masked shrew, the water shrew (one of the few mammals in Michigan that live exclusively in wetland habitats), the pygmy shrew, and the Northern short tail shrew. Of these, the Northern short tail shrew is by far the most common. Shrews are insectivores, feeding off of small insects, worms, centipedes, snails, slugs, and woodlice. Shrews live underground, but will travel above ground and can frequently be seen scurrying through tunnel-like runways in the grass. The are constantly on the move and are constantly eating.

Due to their small eyes and poor eye sight, shrews rely on their sense of hearing and smell to locate prey and avoid larger predators, of which it has many: owls, hawks, weasels and snakes all feed on the shrew. Cats will also kill shrews, but usually do not eat them due to foul-tasting glands in the shrew’s skin which give it an unpleasant smell.

Shrews are very territorial and do not enter each others territory except to mate; however, a shrew’s territory is not that large, and up to 80 shrews can all live within a single acre. Shrews breed from May through October and a female produces at least two litters during this time, each having from 4 – 10 young. They babies grow extremely quickly and are independent at one month old. Shrews can live about 20 months, but most are born, live and die within one year.

Shrew and humans

Shrews do not have a considerable negative impact on humans and go about their lives unnoticed by most people. They do become a concern when they get in close proximity with humans, however. Shrews are naturally very aggressive and will occasionally attack pets, birds or chipmunks at feeders. They sometimes get into the home by falling in window wells or squeezing in tiny entry points. Once inside the home they may feed on stored foods and contaminate them with feces and urine. If you have a shrew in your home, do not attempt to pick it up as they will bite if improperly handled, and there is a risk of disease transmission. If a shrew has gotten into your home, call a wildlife removal professional.

Shrew facts

  • The pygmy shrew is the smallest mammal in North America, averaging only 2 cm. in length, about the width of a quarter.
  • Due to the extreme amount of energy shrew’s use up by their constant activity, they will starve to death if they do not eat every three hours.
  • Because of their very sharp teeth and aggressive nature, shrews are capable of killing animals many times larger than themselves.
  • The word shrew comes from an old Germanic word for “to cut or shred.” The animal was believed to have a malicious influence on people and was dreaded. This led to the application of the term to “peevish, malignant, clamorous, spiteful, vexatious, turbulent women” in the 14th century, as it is used in Shakespeare play The Taming of the Shrew.