Shrews (Soricidae family) are often confused with mice. While the two animals are roughly the same size, shrews are not rodents and do not possess the perpetually-growing teeth of a mouse or rat. Rather, shrews are more closely related to moles and have small, spike-like teeth; some are even venomous.
Most shrews are smaller than the average mouse and only weigh a few ounces. They have a distinctive long snout and pointed nose, dense fur and very small eyes. For their size, shrews have massive brains that make up nearly 10% of their body mass. Their brain to body mass ratio is greater than any other animal, including humans. There are 376 known species of shrew spread throughout most of the world. These active animals are rarely preyed upon due to their extremely vile smell.
Shrews are solitary animals and usually do not socialize for any reason other than mating purposes. They are fiercely territorial and will drive away any other shrew that comes onto their turf. The rest of the time, shrews eat; and they eat a lot. With one of the highest metabolisms of any mammal, shrews must eat 80-90% of their body weight in food every day just to survive. For an average human male that would be the equivalent of eating 150lbs of food every day! Shrews are not picky eaters. Their diet consists of nuts, seeds, insects, worms and dense vegetation. Venomous varieties can poison and kill mice, and some species are capable of hunting prey larger than themselves. A few species are also capable of using sonar – like bats – as a navigation aid.
Shrews make their homes in small burrows or nest usually under the cover of a thicket to prevent detection by predators. Very efficient reproducers, female shrews are capable of having up to 10 litters a year and becoming pregnant again within a month of giving birth. Most shrews live from 1-2 ½ years.
- The masked shrew’s heart beats 1200 times a minute
- The Etruscan shrew is the smallest land-going mammal in the world. Its body is only 3 centimeters long, and it weighs as little as a dime.
Minnesota Department of Natural Resources