In this video adapted from NOVA scienceNOW, learn how the common wood frog survives the cold winter. Wood frogs are found in the northern United States and Canada and must endure freezing cold temperatures for parts of the year. In order to survive the cold, they have a special adaptation—they are able to freeze solid without damaging their cells. Sugar acts like a natural antifreeze in their bodies, allowing them to spend the winter frozen and then resume function in the spring.