There is just one family of ants, the Formicidae. The advanced eusocial ants have diverse life-cycles lasting more than one year. Their nests are found in dead wood, or, more usually, in the soil. Typically, the colony consists of one or more queens with a large number of workers and brood. Males and new queens are reared seasonally. The most common life-cycle starts with the mating flight after which the males die and the fertilised queens shed their wings and enclose themselves in an earthen cavity. Eggs are laid and the larvae are fed by the queen. The first brood consists of workers which help the queen to rear further broods. The larvae are fed by the workers on a wide variety of foods of animal and vegetable origin. When the colony reaches a certain size new queens and males are reared. The colony, however, does not end with the production of the sexuals but can continue for several years rearing further sexual broods. This basic life-cycle can show variations. The newly mated queen may return to the natal colony rather than starting a new colony. Such colonies eventually undergo fission with queens and workers leaving the parent colony to form a new colony. In some species, the newly mated queen penetrates the colony of a different species, usually killing the host queen. The intruder queen lays her eggs which are reared by the host workers. The workers of the intruder queen gradually replace the host workers which eventually all die. Such a life-cycle is call ‘temporary social parasitism’. In `permanent social parasitism' (or inquilinism) the intruder queen generally does not lay eggs that become workers, but only lays eggs which become new queens or males, like the social parasites of social wasps and bees. 11 genera with 51 native species, with a further 1 genera and three species restricted to the Channel Islands, and around 13 introduced species associated with artificially heated environments.