A snake's jaw is linked directly to its inner ear, allowing it to literally hear surface vibrations. Snake jawbones are so sensitive that a horned desert viper can accurately strike at a small, quiet mouse coming up behind him ... in the middle of a pitch-black night. Further, their lower jawbones are separated into two halves, and the difference in timing between the vibrations received by the two sides informs the snake of the direction of its scampering prey. Snakes have high-fidelity directional hearing in their mouths.
Better yet, because snakes "smell" by "tasting" the air with their tongues, and because those tongues are typically forked, they also have incredible directional smelling. Snakes effectively smell in stereo. Finally, many varieties of snake have heat-sensing pit organs that can detect infrared light. For their relatively tiny size, these sensors are up to 10 times more sensitive than anything our technology has managed to create, and they come in several different types that all focus on different wavelengths.
Sichert, Andreas, et al.
"Suck it, Predator."
But pit vipers take it a step further; they not only possess this crazy Predator-vision, but actually use the heat map to direct multiple attacks on a single target. They'll strike their prey once, wait for the adrenaline to kick in, watch for heat spikes that show where their prey is most vulnerable, and then direct their next strikes to the weak spots. You might recognize that as the exact same tactic you use to beat video game bosses. That's right: Pit vipers' whole lives are basically one big round of Metal Gear Solid.