In this photo by Barry, the 'cheeky chipmunk' has cheek pouches stuffed to bursting, as he ferries food to his den. Chipmunks are clever little animals, and in their winter den they maintain not only sleeping quarters, but a larder in which they store food to see them through the winter. This is because they are not true hibernators like groundhogs who sleep the winter away. Chipmunks awake periodically and head over to their larder to have a bite to eat.