How do snakes hunt at night?

Answer 1

Snakes have special organs (pit organ) between their eyes and nose that can sensor infrared's radiation. With this organ it enables it to detect animals that have heat trapped in them (example: mice, birds)

Answer 2

Rattlesnakes "Taste" the air with a special organ called the Jacobson's organ, located inside the nasal cavity. The tongue flicks out and returns scent to the organ, allowing the snake to track its prey. Then, as it draws close, the pit below the eye senses the heat from the rat's body, and the snake can hit the target without seeing it.