I get what you mean, but snakes tend to eat snakes. King snakes are called kings because they dominate and eat other snakes.
Well yea...how much pressure does it take to choke a snake to death? That's what it does.
I don't know. Would it be psi, atm, kbar? Or would it be newtons or foot pounds? I know you can crush a snake with a swift stomp, inadvisable for venomous types. I wonder what the size cutoff for stomping death would be. Surely an anaconda is off the table. 6' rattler still doubtful. Probably more a question of girth, how fat is a 3' rattler?