Dominance is a form of behavior among individual animals that shows their ability to win aggressive encounters with other animals. These animals may be members of the same species or of different species. Dominance determines which individuals have first choice of resources that are needed to survive and reproduce and that are in limited supply. These resources include food, water, a resting place, or mates. Animals that lose the aggressive encounters or give in to dominant individuals without a fight are called subordinates. Subordinates that are denied use of scarce resources may be among the first to die or to leave an area.