Groundhogs, also known as woodchucks, are hibernating underground in their burrows, and their internal clocks will awaken them near the end of March, not on Groundhog Day (Feb. 2). A hibernating woodchuck's body temperature may fall as low as 38 degrees F from a normal close to 100 degrees, they breathe once every six minutes, and their heartbeat is about five percent of normal. The woodchuck is the largest member of the squirrel family, and an adult may be about two feet long and weigh from five to 10 pounds. Its home range is about one-fourth to one-half mile in diameter. It spends most of the daylight hours eating green vegetation and storing up fat so that it can spend the long winter in hibernation. In our area most woodchucks are hibernating by mid-October. These brown furry animals dig a complicated burrow system 25 to 40 feet long, about four feet below ground level.