Least chipmunk, Kootenai National Forest, Montana

The fast and the furriest. Least chipmunk, Kootenai National Forest, Montana

In the world of woodland critters, the least chipmunk might seem like the 'undersquirrel'—but don't count it out. With survival smarts and turbo-charged feet, this tiny rodent proves that being 'least' is no reason to squirrel away your potential. Weighing less than a deck of cards and measuring under 10 inches from nose to tail, this species is North America's smallest chipmunk.

When it's not sprinting up logs or vanishing into leaf piles, it is stuffing its face—literally. Its expandable cheek pouches help it haul seeds, berries, and insects to storage spots. Come winter, it doesn't fully hibernate. Instead, it enters a light torpor, waking every so often for a snack. Not one for group living, each least chipmunk carves out its own territory every summer, usually with a hidden burrow and a backup food cache or ten. But if a predator wanders too close, you'll hear chip-chip-chip alarms sounding off.

Did you know that a least chipmunk's memory is so sharp that it can remember the locations of hundreds of food caches, even after a long winter nap? So next time you forget where you parked, just remember—a chipmunk wouldn't have.