A group of ants is called an army or a colony. The size of the colony will depend on the environment and the conditions of the area.
Some colonies of ants are bigger than others, but it is not unusual for one to contain literally thousands of ants. In Japan and some parts of the United States, colonies have been found containing more than 300 million ants. Like people, ants all have different tasks within the colony. The queen only lays eggs and males are limited to mating with the queen. The female ants are responsible for the rest of the tasks including gathering food, feeding the young, and depending the colony from predators. Unlike many insects, ants are found in all parts of the world.