Pale underbellies are most often found among animals that need...

Pale underbellies are most often found among animals that need to worry about danger from below. Creatures that swim, fly, or climb may blend into the background water or sky above if their bellies are light. Animals can also benefit from a camouflage concept called countershading. By having darker pigment on the part of the body that receives the most light and lighter pigmentation on the part that receives less light, the animal’s appearance tends to flatten out and is less conspicuous. But what explains the softness? (via Slate)