Animals of the same animal species, living in the same area, and interbreeding with one another, are referred to as a population. The size of a population and the area it occupies may vary over time due to disease and competition from other animals. The term population includes animals that live on their own, sometimes roaming over a wide area, animals that form a family group, or a larger group, such as a colony. Some groups are temporary and only form during the breeding season.
Cheetahs have complex societies. Males may roam from place to place, or claim their own territory. They live on their own or in pairs. These pairs, which are often brothers, live and hunt together throughout their lifetime. They sometimes claim territory that overlaps that of females, marking the boundaries with their urine on trees. Male and female cheetahs mix only when they mate.
Meerkats are mongooses that live in groups called troops. Each troop contains several family units and occupies a territory, which they defend together from neighbouring meerkats and predators. One or two individuals act as sentinels. They climb onto the nearest high place and look out for danger.
Termites live in colonies of over a million members, in large mounds. The members are all descended from a single queen and her mate and they only survive if they work as a team. A queen termite lays some 30,000 eggs each day. She is dependent on the worker termites to look after her and her eggs. Other termites, the soldiers, defend the mound from attack, using their powerful jaws to bite any intruders.