If your boy shouts, "Wow, I killed him!" or something like that, there is nothing wrong with him—he is just a boy. But he should understand that what he just killed wanted to live as badly as he does, and that he should feel sorrow as well as triumph. Other children will not relish death. If they kill, they will likely be saddened by it. This is natural too. Some youngsters are horrified by death and by the prospect of causing it. They are not meant to be hunters. They are no less courageous or worthy than kids who itch to hunt—they are simply different, and you must respect that.