Queen ants are egg laying specialists. They are responsible for continuously laying eggs that will develop into either worker ants or another queen ant. An ant colony has three castes: male, female, and worker ants.

A queen ant can intentionally lays eggs that are fated to mature into a specific caste. An egg that is unfertilized will likely become a male ant while a fertilized egg that develops into an undernourished larva will become worker ants. The degree of fertilization and nourishment are the criteria for the development of either a worker ant or a queen ant. A potential queen ant will develop from a well-nourished larva.

One example that exemplifies this is the queen ant from the ant species Formica japonica. The male ant partner will transfer all his sperm cells via his seminal vesicle into the queen ant during the mating flight. The queen ant will receive all the sperm cells she will need for her lifespan. It is the queen ant's decision to whether use all the sperm cells or to fertilize it or not for the time being. Her decision to use or fertilize the eggs all depends on the need, as perceived by ant, of the colony.