Snakes have near-zero eyesight, but they are extremely agile and have a strong ability to catch their prey, even in the dark of night, they can detect and accurately capture voles moving dozens of meters away.
When scientists studied snakes, they found that snakes use a cheek socket between their eyes and nostrils to "heat locate". Some people have done two ingenious "snake experiments", the first of which involves destroying the hearing, sight and smell of a five-step snake and then placing an electric light bulb wrapped in black paper in front of its eyes.
When the light is turned off, the snake is quiet, turn on the light, and the snake becomes alert. When the light bulb was moved closer to the snake's head, the snake pounced on the black-rumbling "hot guy" like lightning. Another test involves anesthetizing the snake, then stripping off a nerve leading to the cheek socket of the face, exposing it to the snake's body, and measuring the bioelectrical current of the nerve with an instrument. When the head of the snake is approached with a hot object, the cheek socket becomes excited. When irradiated with infrared rays, the excitement of the buccal socket reaches a climax, which exceeds that of other forms of stimulation. Apparently, the snake relies on this "thermally localized" organ in the dark of night to catch its prey.
When a thermo-blooded critter like a vole comes near a snake, the infrared rays radiated by their bodies, albeit with only a slight change in heat, allow the snake to quickly spot its target and capture it with unerring accuracy in the darkness where it is not visible. Inspired by the snake's "hot eye" function, scientists have designed a variety of infrared automatic tracking devices, which can be used in guns, ships, airplanes and even technology.