Wood Frog

I’ve been preparing a presentation for a school about nonfiction writing, based on Save the…Frogs! and it occurred to me that I have not yet posted about the wood frog.

Such a simple name, such an unassuming appearance–but this frog is amazing. It lives north of the Arctic circle and in the winter it freezes. It’s a frog-shaped lump of ice. In the spring it thaws out and hops back to a perfectly normal form of life.

How can it survive being frozen? Turns out one reason freezing is so deadly is that ice expands. Freezing a living being means that when water inside the cells freezes, it ruptures the cell’s membranes.

But the wood frog can replace most of its internal water with glucose. Glucose does not expand when frozen. So the frog freezes, thaws, and lives.

Frogs really are incredible.