Why Snakes Will Dance During A Snake Charming Performance?

In movies, we sometimes can see snake charming performance in which snakes will dance when those so-called healers or magicians play a special musical instrument called pungi. However, snakes do not have external ears so they cannot hear any sound. They only have a hearing organ which is connected with their jaw bones, and that organ enables them to detect vibration surrounding them. However, that is not the reason for snakes swaying back and forth with the music. When the snake charmer is playing and waving the instrument called a pungi, snakes can see the motion of the pungi and charges at it in a defensive mode. So, instead of enjoying the music, snakes feel threatened and become anxious when the charmer moving the instrucment. Due to the fact that snakes have a poor vision, snake charmers have to sit close to the snakes so that they can see it clearly. That can also explain why snakes are attracted by the movement of the instrument instead of being hypnotized by the music.