Groundhog hibernation gave rise to the popular American custom of Groundhog Day, held on the second of February every year. Tradition dictates that if a groundhog sees its shadow that day, there will be six more weeks of winter, though such a prediction seems a sure bet over much of the groundhog's North American range. In the spring, females welcome a litter of perhaps a half dozen newborns, which stay with their mother for several months.
Groundhogs are the largest members of the squirrel family. Though they are usually seen on the ground, they can climb trees and are also capable swimmers. These rodents frequent the areas where woodlands meet open spaces, like fields, roads, or streams. Here they eat grasses and plants as well as fruits and tree bark. Groundhogs are the bane of many a gardener. They can decimate a plot while voraciously feeding during the summer and fall seasons.
Mostly herbivorous, groundhogs eat primarily wild grasses and other vegetation, including berries and agricultural crops, when available. Clover, alfalfa, dandelion, and coltsfoot are among preferred groundhog foods. Groundhogs also eat grubs, grasshoppers, insects, snails and other small animals, but are not as omnivorous as many other Sciuridae. Like squirrels, they also have been observed sitting up eating nuts such as shagbark hickory, but unlike squirrels, do not bury them for future use. Ernest Thompson Seton wrote that so far as he knew, the groundhog does not drink water but, like the rabbit, satisfies the need for liquid with juices of food-plants, aided by their sprinkling with rain or dew. Schoonmaker said it is possible groundhogs enjoy the rain water that clings to plants because so far as he was able to determine, groundhogs do not drink and it seemed the juices of plants supplied the needed liquid.