From what I understand of how snake's muscles work Mina it's very normal. Their long bodies with the muscles that create the constriction pressure are very energy efficient. Those muscles draw a huge amount of energy however so this ability to "pulse" that energy when needed is a way to control the loss of it (if that makes sense). For me it seems to be like a t-stat that flips on and off, compared to one that proportional....both can achieve a goal but one if far more efficient than the other.

The more I research how snakes work the more fascinated I'm becoming with how incredibly well designed they are.