just because one feeds f/t doesn't mean that one doubts a snakes ability to catch and kill a live prey item. It does however prevent the slim chance that a prey item can bite back and injure the snake in the process. That's something we can do as responsible keepers is help prevent any un-necessary harm to our animals. It comes down to personal preference of the keeper and the snake, cause ultimately they have the last word on what they're going to eat.