The groundhog, often called a woodchuck, is the largest member of the squirrel family. This mammal is widely distributed across North America, from the southeastern United States up into Alaska. Built for digging, the groundhog’s life revolves around a seasonal cycle of excavation, foraging, and deep dormancy. Its activities are centered on maximizing energy intake during warm months and conserving it during the cold.
Constructing the Underground Home
The groundhog spends the majority of its time engineering burrows. These tunnels provide shelter from weather, protection from predators, and a safe nursery for raising young. Tunnel systems often extend 20 to 65 feet in total length and reach depths of 2 to 6 feet below the surface.
A typical burrow includes one main entrance, usually marked by a visible mound of excavated soil. To ensure a quick escape, groundhogs incorporate several auxiliary, or plunge, holes. These holes are often camouflaged and excavated from below so no dirt mound reveals their location. Within the tunnel system, the groundhog maintains dedicated chambers for specific functions. These rooms include nesting areas lined with grass, a sealed-off latrine chamber for waste, and a hibernation den.
Daily Diet and Foraging Habits
During the active months, groundhogs follow a diurnal routine, focusing their energy on foraging. They are primarily herbivorous, consuming plants to build up the necessary fat reserves for the upcoming winter. Their diet heavily features grasses, clover, alfalfa, and common garden vegetables like peas, beans, and carrots.
Peak times for foraging are typically early morning and late afternoon. The groundhog often retreats to its burrow for a midday rest during the hottest parts of the day. They feed very close to the burrow entrance, rarely venturing further than 150 feet from their home. This proximity allows for a rapid retreat if a predator is spotted. While their diet is dominated by plants, they occasionally consume small amounts of insects, such as grasshoppers and June bugs, and available fruit like berries and apples.
Specialized Seasonal Behavior Hibernation
The defining annual activity for the groundhog is its period of true hibernation, a unique physiological state. Groundhogs typically begin this deep dormancy in late fall, around October, and remain inactive until late winter or early spring, often February or March. This process begins with intense eating during the summer and fall to build up the substantial fat layer needed to sustain them.
As the groundhog enters hibernation, its bodily functions undergo a dramatic reduction to conserve energy. The normal body temperature of approximately 99 degrees Fahrenheit drops drastically to as low as 37 or 38 degrees Fahrenheit, barely above freezing. Their heart rate plummets from an active rate of around 80 beats per minute to just 4 or 5 beats per minute.
This deep state of metabolic depression also affects respiration. The breathing rate slows from about 16 breaths per minute to as few as 1 or 2 breaths per minute, or even one breath every five minutes. The animal loses up to half of its body weight by the time it emerges. The traditional emergence around February 2nd, the date of Groundhog Day, is closely linked to the end of their hibernation, as males are among the first to wake up in preparation for the spring breeding season.