Ants tending to eggs and larvae. Close-up of a colony of ants (family Formicidae), larvae and eggs in a nest. Ants are social insects, living in colonies that can contain up to several million individuals. Each colony shows a high degree of social organisation, consisting mainly of sterile female worker ants plus some fertile males and females. All of these are the progeny of a single large female known as the queen. A new worker spends the first days of its adult life caring for the queen and young. Then it graduates to digging and other nest work, and then to foraging and nest defence. The nest is made up many chambers, which are connected by small tunnels. Some chambers function as rooms for nurseries, food storage, and mating. Photographed in Pichincha, Ecuador.