Wood Frogs (Lithobates sylvaticus) Freeze Solid Over Winter and Then Come Back to Life in Spring
Here in North America there are a wide variety of toads and frogs but perhaps none are so unusual as the wood frog. These frogs are found in Eastern North America, Canada, and up into Alaska. On a warm spring night you might hear them singing(click her for sound clip) near bogs, vernal pools, or upland forests but something remarkable happens to them this time of year in the winter, they freeze solid. Now freezing solid isn't remarkable by itself, but what is remarkable is that the frogs will literally come back to life in the Spring after having no heartbeat or brain activity, and they don't breathe, for up to eight weeks! This baffles and amazes scientists, who are actively studying them even now.