Why do Groundhogs whistle?
Groundhogs live in widely branched burrows below the ground, but come out on the surface every day to collect grasses, seeds, and insects. A few species live in colonies in high mountains. They divide work amongst them – when a few animals have gone out in search of food, the others are on guard. If they sense danger from approaching enemies, they emit a shrill whistle to warn the others. In the summer, the animals must feed enough to put on a thick layer of fat so that they can survive the 6 – 9 months long winter sleep.