Frogs are found all across the world, but only one species lives as far north as the Arctic Circle: the wood frog. That might surprise anyone who’s seen the small, brownish amphibians in Alabama or Georgia, but these tiny creatures are as widespread as they are resilient. They've adapted to cold climates (including Alaska and the Northeast) by literally freezing during the winter, with their hearts no longer beating and their lungs no longer breathing air as they enter a kind of suspended animation. How, then, do they not die? By producing a sugary sort of antifreeze that keeps their actual cells from freezing — which would be lethal — even as the space between their cells does. They thaw out when temperatures rise in the spring, ready to live their best frog lives (read: mate) once again.
Most other animals in the Arctic are a little less surprising: polar bears, walruses, musk oxen, and other hardy creatures are well-suited to harsh conditions. None of them need to freeze in order to survive the winter, which only makes wood frogs more impressive. Their ability to make it through the season unscathed — which has been described as a biological miracle — also has to do with location. Wood frogs nestle on the leafy litter of the forest floor, hiding from potential predators and partially insulating themselves from the cold to come.
