Of all the wonderful adaptations in the animal kingdom, perhaps the most important is the habit of living together in communal or family groups. Animals can derive a lot of benefit from spending time with other members of the same species. They can help each other find food, defend against predators and care for young. Countless species engage in group living, either in herds, colonies, harems, complex societies or loose associations. But perhaps the simplest and most common form of group living in the natural world is that of nuclear families, which may consist of a male/female couple with their young, a single male and various females and young, a group of females and their young, or whatever combination works best.