AP Photo

The animal kingdom boasts many an impressive form, from arching giraffe necks to spoon-shaped bird beaks to gigantic beetle claws. But evolution has worked on much smaller scales too, producing finely honed nanostructures--parts less than a millionth of a meter across, or smaller than 1/20th of the width of a human hair--that help animals climb, slither, camouflage, flirt, and thrive.