green frog on brown wooden surface

The gray tree frog is native to much of North America and southeastern Canada. They have a remarkable ability to camouflage, changing in color from bright green to dark brown to pale tan. During a winter freeze, the gray tree frog will freeze to the point his heart and lungs will stop. The frog survives by producing large amounts of glycerol, which changes to glucose, spreads to the cells, and prevents them from dehydrating during the freezing process. There are only 5 known species of frog with this ability in North America.