Shrews are tiny, high-energy mammals belonging to the family Soricidae. Unlike rodents, which have gnawing incisors, shrews are insectivores with sharp, spike-like teeth and a long, pointed snout. They possess one of the highest metabolic rates in the animal kingdom, requiring them to consume between 50% and 300% of their body weight in food every single day. While the question of whether shrews burrow is common, the direct answer is that they do not typically excavate extensive, deep tunnel systems like a mole. Instead, they are opportunistic users of existing subterranean pathways.
Shrew Tunnel Use and Shallow Digging
The shrew’s demanding metabolism makes the constant, high-effort work of digging deep tunnels inefficient. Maintaining a near-constant state of hunting for invertebrates like worms, spiders, and grubs is paramount, which is better accomplished using established routes. Shrews readily travel through and forage within tunnels created by other animals, such as voles, mice, and especially moles.
The type of digging shrews perform is primarily focused on foraging and creating temporary shelter. They dig very shallow, small runs just beneath the leaf litter or thin topsoil layer, often referred to as surface tunnels. Occasionally, a shrew creates a small, inconspicuous entrance hole, typically only an inch in diameter, to access a mole’s deeper tunnel system or quickly disappear from a predator. These shallow burrows rarely extend more than a few inches deep and are not part of an extensive, constructed network.
Nesting Sites and Surface Movement
Since shrews do not construct complex, deep burrow systems, their living quarters are generally located at or near the ground surface. They prefer habitats that offer dense cover and natural protection, such as thick vegetation, heavy leaf litter, beneath logs, under debris piles, or within rock walls. A common shrew’s nest is a small, spherical structure, typically the size of a baseball, composed of shredded materials like grass, leaves, and other soft plant matter.
These nests serve as protected sites for resting and for raising young, and are usually situated in a naturally existing cavity or a shallow chamber. Female shrews may have several litters a year, and the majority of a shrew’s time is spent moving actively on the surface or just below it, constantly hunting. Their movement is characterized by a frantic, darting search pattern, covering an extensive home range in a perpetual quest for food.
Identifying Shrew Signs Versus Other Mammals
A common source of confusion for homeowners is distinguishing shrew activity from the signs left by other subterranean mammals like moles and voles. The most definitive sign that a shrew is not the primary excavator is the complete absence of the large, conical dirt mounds or “molehills.” These volcano-shaped piles of earth are characteristic of moles pushing soil to the surface during their deep tunneling.
Mole activity is identified by the visible, raised ridges that crisscross a lawn, which are the subsurface tunnels moles use for hunting. Vole activity, conversely, is marked by clear, narrow surface runways—defined paths through the grass that voles use for travel and feeding. Shrews, in contrast, leave only small, inconspicuous entry holes, often about one inch wide, that lead into existing tunnels or shallow foraging scrapes. If you find small holes without accompanying large dirt mounds or extensive surface paths, the activity is more likely attributable to a shrew opportunistically utilizing the landscape.