First, it literally shrinks. Beginning in late autumn, a shrew’s skull, brain, and several internal organs get smaller — up to one fifth of their summer size. With less tissue to warm and maintain, the animal’s daily fuel drops just enough to stretch the limited supply of winter insects and worms. Come spring, everything grows back to normal. Scientists call this reversible shrinking Dehnel’s phenomenon — nature’s version of turning down the thermostat until the weather improves.

Shrews also change their daily routine. In summer they defend territories fiercely, chasing off intruders to protect food stashes. In winter they relax slightly. Several shrews may overlap their feeding routes or share snug nests made of dry leaves under logs or in grassy tussocks. By tolerating neighbours, each individual shrew spends less energy on fights and more on foraging. They feed primarily on insects, worms, and other invertebrates, relying on a keen sense of smell and touch, as its eyesight is poor. The shrew’s elongated snout and constantly twitching nose help it detect prey in the soil and under leaf litter.

There isn’t often heavy snowfall in Hampshire and the Isle of the Wight, but when it lays, finding food under snow is tricky for wildlife. Shrews exploit the “subnivean zone”—the narrow airspace between soil and compressed snow. This hidden corridor stays just above freezing and is rich in dormant insects and larvae. Guided by a twitching, highly sensitive snout, a shrew zips through these tunnels almost nonstop, pausing only for brief naps of a few minutes.

Though a common shrew lives barely a year, its winter strategy is a masterclass in adaptability: shrink the body, share the space, and keep moving. Against icy odds, through relentless foraging, territorial instincts, and seasonal adaptation, this tiny creature embodies the raw, instinctual will to survive in nature’s complex web.