Found a Wooly Bear caterpillar curled up cozy in the wood pile the other day. I carefully placed him under a hunk of bark in the woods. I have loved these critters since I used to find them with my Mom as a young kid.
They contain a cryoprotectant that keeps them vital during their winter hibernation. When it warms up, they will wake up and eat like crazy, pupate, and become a tiger moth - the Isabella Moth.