Colonies begin in spring with a single fertilised queen, who makes a nest with a single egg in each of a small number of cells. These eggs hatch into grub-like larvae that are tended by the queen for the few weeks it takes them to reach maturity. This first batch of workers takes over nest construction and rearing larvae, and the queen concentrates on egg-laying. The nest continues to be extended throughout summer.
Towards the end of summer, several larger cells are constructed, in which a new generation of queens develop. Males also develop, and mate with the queens outside the nest before they die.
In late autumn the original queen dies, and the new queens disperse to find suitable over-wintering sites before forming a new nest in spring. It is significant that in the warmer climate of Australia, one of the new queens may stay in the nest and begin laying eggs, without the usual winter hibernation period. Over several seasons, this can result in giant nests containing more than 100,000 wasps.