In nature, the vision of rattlesnake is almost zero, but the buccal fossa organ on its nose has the function of thermal positioning, which can sense the temperature difference of 0.00 1 degree Celsius, and the reaction time does not exceed 0. 1 second. Even if reptiles and small animals are sleeping at night, rattlesnakes can quickly perceive their position and prey according to the heat energy emitted by these animals.