Shrews are small, insectivorous mammals often mistaken for mice or voles. They are characterized by a long, pointed snout, small eyes, and soft, velvety fur, distinguishing them from stout-faced rodents. Shrews have an unusually high metabolism, forcing them to be constantly active and maintain a voracious appetite. Due to this high energy requirement, they must consume a significant amount of food, often eating anywhere from half to three times their own body weight daily. Their presence in the landscape is a direct result of their relentless search for prey.
Shrew Diet and Natural Pest Control
The shrew’s demanding metabolism makes them highly effective biological controllers of garden pests. Their diet consists almost entirely of protein-rich invertebrates, positioning them as natural predators for destructive yard inhabitants. They actively hunt and consume a wide array of soil-dwelling pests, including slugs, snails, spiders, earthworms, centipedes, and millipedes. This predatory behavior also extends to insect larvae, such as cutworms and white grubs, which destroy turfgrass and plant roots.
Shrews can destroy hundreds of insect larvae in a single day. They also occasionally prey on small vertebrates, including mice, snakes, or frogs. By focusing their hunting efforts on these garden nuisances, shrews provide a continuous, chemical-free form of pest management that often outweighs the minor disturbances they cause.
Specific Effects on Landscaping and Structures
While shrews offer natural pest control, their constant foraging activity can disrupt a yard. Searching for subterranean prey, shrews create small, shallow, erratic tunnels just beneath the soil surface. These tunnels are not the raised ridges characteristic of moles, but they can disturb the uniformity of a lawn or garden bed. Shrews often utilize the existing tunnel systems of other burrowing animals.
Digging for insects can result in small, dime-sized entrance holes and the uprooting of young plants or seedlings. If insect food is scarce, some shrew species may opportunistically gnaw on the bark of small trees or contaminate vegetables. Shrews may also enter structures like garages or sheds in search of shelter or food, and their presence is often accompanied by a pungent, musky odor from their scent glands.
Identifying Shrew Activity Versus Other Pests
Homeowners frequently mistake shrew activity for that of moles or voles, making accurate identification essential. Shrew tunnels are much smaller and more random than the deep, symmetrical networks created by moles. Shrews leave small, one-inch diameter holes as entrances, especially in areas with dense ground cover. Moles, in contrast, are the primary culprits behind the noticeable raised ridges and volcano-shaped mounds of soil in a lawn.
Physically, a shrew is identified by its long, pointed, mobile snout and delicate forefeet, unlike the broad, paddle-like front feet of a mole. Shrews are also much smaller than moles, measuring only three to five inches in body length. Unlike voles, which are herbivores with blunt faces, shrews possess a slender snout and are strictly insectivorous. A unique sign of shrew presence is their corkscrew-shaped droppings, which may be found near their foraging paths.
Non-Lethal Methods for Shrew Management
If shrews become a persistent nuisance, non-lethal management focuses on making the yard less appealing as a habitat. The most effective strategy is habitat modification, which involves removing dense ground cover, rock piles, wood stacks, and other debris that provide shelter for shrews and their prey. Keeping the lawn mowed to a short height also reduces the protective cover shrews prefer for their runways.
Reducing the shrew’s food source is another practical approach, achieved by controlling the population of grubs and other soil insects they hunt. Exclusion methods should be used to prevent shrews from entering structures, such as sealing foundation cracks and small openings with quarter-inch hardware cloth or coarse steel wool. Commercial repellents containing ingredients like castor oil may deter burrowing animals, though no specific repellent is registered solely for shrews. If necessary, small, humane live traps can be used and baited with high-protein food like peanut butter and oats for relocation.