Snap traps won't catch a mouse by the tail, unless he eats with his tail. They show that in cartoons because they don't want to acknowledge what they really do. They're designed to snap mousie's neck, and that's what they do, when they work. As mentioned earlier, there is no nice way to kill a critter, and this is at least fast and reliable, and the mouse won't see it coming.
I used catch-and-release traps in my old house, where we had quite the infestation. I would carry the mice blocks away and then watch them run as fast as they could back to the house when I released them.
