Difference between zaroff and rainsford

Both are hunters, but one has some sense of morality and one has no sense of morality (Zaroff) and hunts only to please himself. Both have the survival desire, but Rainsford realizes (and asks the questions early in the story)that perhaps animals have feelings. His being hunted by Zaroff makes him know that the survival of the fittest is in fact part of the law of the jungle.