Talk about environmental awareness — these animals don't just know their surroundings, they are their surroundings. Or at least that's what their enemies think.
Camouflage is an ancient art, likely not much younger than vision itself, and species around the planet depend on it daily for survival. Whether it's a gecko blending into bark, a jaguar fading into foliage or a Peringuey's viper sliding through sand (pictured), good camo can mean the difference between eating and being eaten. Humans have learned many lessons from Mother Nature's masquerades over the years, but as the following photos suggest, there's also plenty we haven't seen.
Editor's note: This slideshow has been updated since it was originally published in March 2011.