Groundhogs, or woodchucks, live in Canada, Alaska and the eastern part of the United States. A member of the marmot family, it is found in forests, pastures, fields and woodlots, where it digs dens. It often has a summer and a winter den.
The groundhog's summer den is dug close to a good source of food, while the winter den is chosen as a good hiding place, as the groundhog hibernates during the winter. The dens usually have more than one entrance and exit and are riddled with tunnels and chambers.
Male woodchucks usually have a home range that's about 33,000 square feet, while females have a home range of about 8,200 square feet. This area is enlarged after the female gives birth. The male home range usually encompasses the home ranges of a few females. However, woodchucks are solitary outside of the mating season, and may threaten each other if they encroach on each other's territory.
Woodchucks use bodily secretions from facial and anal glands to mark off the boundaries of their territories.
Groundhogs have been known to return to hibernation if they emerge from their dens too early in the season. Because of this, people believe they can predict how long winter is going to last. This has given rise to the tradition of Groundhog Day.