Shrews are very beneficial to the environment. They keep a good handle on insect pests including snails, mice and foliage destroying pests such as the larch sawfly. Because owls have a less developed sense of smell, the odor of the shrews does not bother them and shrew represents a very important prey animal for owls.
That poisonous bite, while not lethal to humans and domestic pets, can lead to some very painful days and perhaps an expensive trip to the doctor. Shrews can also cause problems when they decide to take up residence in building foundations and not necessarily because of structural damage, because of the unpleasant odor of the shrew.