Shrews

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Shrews are often confused with mice or voles, but are more closely related to moles. Both shrews and moles belong to the order Insectivora. While shrews are not attractive and are potentially dangerous, left alone outdoors they will help control insects and rodents in your yard.

HOW DO I KNOW IF I HAVE SHREWS?

  • Most are shrews are nocturnal and not usually seen unless they find their way indoors

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    Shrews are quite vocal and you can hear their high-pitched squeaks

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    Northern short-tailed shrews prefer to tunnel below ground, through fallen leaves, or along frozen ground under snow cover.

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    Shrew nests are up to 8” in diameter underground or underneath a log. Their nest is kept clean, with wastes deposited outside the nest. Other parts of the tunnel system are used for food storage.

WHAT DO SHREWS LOOK LIKE?

  • Shrews have long pointed noses, dense velvety fur, and black beady eyes.

  • They have five toes on all feet. (Mice have only 4 toes on their front feet.)

  • Shrews also have a revolting odor.

The most common shrews in Minnesota are:

The masked shrew (Sorex cinereus)

  • One of the smallest common mammals in Minnesota

  • Grey-brown in color with a light grey underside

  • Tail is brown on top, pale underneath, and a dark tip

  • The body is not quite 2” in length and a tail that is equal in length to the body

  • The masked shrew weights approximately 0.15 ounce

  • Its teeth are brown tipped

 The short-tailed shrew (Blarina brevicauda)

  • Approximately 5” in overall length

  • A short tail that is about 1” in length

  • Short tailed shrews weigh 0.53 to 1.06 oz

  • Males are slightly larger than female

  • Fur is thick and velvety, and can be black, brownish black, or silvery gray, with a lighter and grayer underside

  • Short tailed shrews are venomous. (With the exception of an Insectivore found in Cuba and Hispaniola, the Short tailed shrew is the only venomous mammal in North America.)

ARE SHREWS DANGEROUS?

  • Yes. Do not attempt to pick it up a shrew as they will bite if improperly handled.

  • A shrew bite is painful and can produce painful swelling for several days.

  • Shrews can potentially transmit diseases and parasites, but there are no documented cases.

  • Shrews are naturally very aggressive and will occasionally attack pets, birds, or chipmunks at feeders.

CAN MY HOUSE BE DAMAGED BY SHREWS?

  • Generally, shrews do not cause damage to property.

  • Once inside the

    home

    they potentially may feed on stored food and can contaminate it with feces and urine.

WHAT DO SHREWS EAT?

  • In order to maintain their body temperature, shrews must feed voraciously, night and day.

  • Each day, shrews eat up to their body weight in earthworms, centipedes, snails and slugs, beetles and bugs, spiders, certain fungi and vegetable matter, and even small mammals.

  • Shrews have tiny, but very sharp teeth which they can use to bite and tear flesh.

  • Because of their very sharp teeth and aggressive nature, shrews are capable of will attacking and killing mice, voles, and other animals several times larger than themselves.

HOW OFTEN DO SHREWS REPRODUCE?

  • Shrews breed from May through October

  • Female short-tailed shrews give birth to at least two litters per year, each having from 4 – 10 young.

  • Masked shrew Females have one litter of 6-7 young during the breeding season.

  • The young shrews are suckled for up to 25 days before the babies are weaned.

  • Baby shrews mature extremely quickly and are independent at one month old.

  • Shrews can live two years, but most are born, live and die within one year.

8 INTERESTING FACTS ABOUT SHREWS: 

  • The Etruscan Shrew (Suncus etruscus ) which is about 1.5” in length and weighs 0.07oz is the smallest living terrestrial mammal.

  • The Etruscan shrew’s heart beats 1,511 times a minute; faster even than a Blue-throated hummingbird’s (1,260).

  • Shrews are easily startled and will jump, faint, or drop dead at a sudden noise.

  • Shrew venom is not conducted into the wound by fangs, but by grooves in the teeth.

  • Shrews have poorly developed eyesight, but have exceptional senses of smell and touch.

  • Cats will kill shrews, but usually will not eat them because of the foul-tasting glands in the shrew’s skin which give the shrew an unpleasant smell.

  • Shrews are aggressive and territorial. A new shrew will be killed within a few hours of being placed in a cage with an already established shrew. A pair of shrews simultaneously introduced into a cage will take less than 4 months before one kills the other.

  • The word “shrew” comes from the Old English form of the word was screawa, or shrew-mouse. The Middle English form was shrewe, meaning an evil, ill-tempered, or scolding person (usually female); most familiar use is Shakespeare’s The Taming of the Shrew.