How does a constrictor know when to let go?

[alessia55]

Originally Posted by Will0W783

However, when we condition our snakes to eat f/t prey, they instinctually know they must coil and "kill" it, but there is no signal of death...the prey never suddenly relaxes as it's already dead and limp. Without that signal, the snake doesn't instinctually know when to let go and must judge.

This is a good point. When you feed f/t, the snake never really sense a struggle (unless you're pulling the mouse by the tail at that point), and may still coil around it for minutes. Others somehow pick up the notion that the rat is dead, and just start eating it without ever coiling it.

[DragonsEye]

Can't remember the actual source, alas, but I have read that it has indeed been determined that prey death, as Knox mentioned, is due to the heart stopping as a result of insanely high blood pressure not to asphyxiation.

Highly unlikely that a snake is detecting heartbeats. Rather when the prey stops moving/struggling its dead and time to eat. Why would a snake bother constricting f/t prey? Simply an instinctual response.