Studies of wasp colonies have found that efficiency of many tasks increases as colony size increases. A founding queen must build her nest, and feed her brood while acting alone. The queen must forage for wood, turn the wood into pulp and construct cells, a process that takes many trips. Once the cells are built, the queen must alternate between defense of the nest and foraging to feed her brood. After the brood becomes adults, some individuals can stay with the nest performing building and brood defense tasks. As the size increases, the task of building cells is further subdivided. Wasps that specialize in foraging carry larger loads and make fewer trips to accomplish the same work saving both time and energy. Workers that specialize in pulping and nest building are able to complete their work more quickly. In insect societies as in human societies, division of labor by individuals that specializes makes the colony or society more efficient.
Jennifer H. Fewell & Jon F. Harrison. Scaling of work and energy use in social insect colonies. Behavioral Ecology and Sociobiology. pp 1-15.