Answer:
A combination of careful gardening, naturally high mortality rates, and predatory methods may or may not end the presence of the beneficial northern short tailed shrew [Blarina brevicauda] in a garden. But the combination of cold weather, habitat loss, and natural predators tend to be effective controls on their own. In fact, it's estimated that a little over 5 percent of an area's shrew population makes it through a year.
The garden needs to be free of fallen plant body parts, the lawn needs to be kept closely mowed, and both need to be free of weeds and unnecessary vegetation. That's because fallen leaves, grass clippings, and vegetation above surface level in height may serve as homes and hiding places for shrews.
Predatory methods include encouragement of the shrew's natural enemies and the setting of traps. Specifically, raptors and domestic cats and dogs kill shrews even though they don't tend to eat their victims. Common raptors include eagles, hawks, owls, and vultures. Other natural enemies that gardeners may not welcome include weasels, skunks, raccoons, and opossums.
Snap and pit traps may work with just peanut butter as bait. A pit trap tends to be more effective and more humane. It consists of a big jar or large can dug into the ground, until the lip is at ground level, along shrew routes. The most popular shrew meeting places may be identified by their fecal matter. The container bottom is lined with cotton batting to avoid crippling or death of whatever may fall in. The lip is coated lightly with bacon grease. The lip and the opening are covered with a light layering of grass. The location needs to be checked regularly.
Any trapped shrew needs to be released no less than 200 yards/193 meters away from the gardener's property. That's because the shrew is a beneficial predator of insects, slugs and snails.