Frogs are especially powerful hibernators, and can actually come back to life after freezing completely. Oftentimes, frogs will partially or entirely bury themselves within the soil on land in order to stay warm, while others seek out shelter in nooks and crannys in logs and rocks. Frogs livers form their own kind of "antifreeze" by producing a large amount of glucose. This increases blood-sugar levels and prevents the formation of ice crystals, protecting the frogs tissues from damage if they do freeze.
Frogs can be almost completely frozen, with no heart beat or brain activity, and still come back once things warm back up!
