How does the praying mantis see?

Praying mantises see through a pair of large, compound eyes. They can turn their heads 180 degrees to veiw what is happening behind them. Since their eyes are too close together, they don't have very keen depth-perception from a stand-still perspective, so they often wave their heads back and forth in a side-to-side motion in order to measure percisely how close or far away an object is, much like a cat does when it's about to pounce.