The spotted hyena is the largest member of the Hyaenidae. They are the most social Carnivora animals, with various group sizes. Hyenas are pack hunters. Their behaviors are still not well understand. However, their social system is not cooperative but competitive. Females take care of their own cubs only, and males are not interested in helping females with their cubs. Females are larger than males and they can control them. The females are the only mammalian species not to have a vaginal opening.