how do snakes really eat the feeder mice and rats?
They swallow them whole. Snakes have the ability to unhinge their jaws so they can actually swallow things bigger than their head.
Constrictors like Boas, strike, then coil around the feeder animal, slowing squeezing until the prey suffocates, Then they swallow the prey head first. Pit Vipers strike and then usually turn loose of the victim, letting the venom do it's work, then swallow the prey animal head first. Fascinating to watch, but you can't help feeling sorry for those poor unsuspecting mice and rats.