Deep Look | The Snail-Smashing, Fish-Spearing, Eye-Popping Mantis Shrimp | Season 3 | Episode 20 | PBS

The killer punch of the mantis shrimp is the fastest strike in the animal kingdom, a skill that goes hand in hand with its extraordinary eyesight. They can see an invisible level of reality using polarized light, which could lead to a breakthrough in detecting cancer.