How Do Ants Reproduce?
The ant colony is divided into three castes: queens, males, and workers. The queen and the males are responsible for reproduction. The workers are sterile females and do not reproduce or participate in egg laying.
New Colonies Started Through Nuptial Flight
The queen will lay worker eggs until mating season at which time she will begin to lay winged males and winged fertile females (alates), which will become queens once they have mated. When the males and queens hatch, they are known as swarmers and will fly away from the nest to mate in a ritual called nuptial flight. The nuptial flight usually occurs during high humidity following rain when the temperatures have reached 70°-95°Fahrenheit. [Fire Ant Morphology, Reproduction, and Development ." UMass eXtension]
The male will die soon after mating. The new queen will find a safe location to lay her eggs. As the sole colony member at this point, she will care for the eggs by herself through the larval and pupal stages. Once this first set of offspring are grown, the queen can focus on egg laying and her workers will care for the new eggs and a new colony is established.
Fertilized versus Unfertilized Eggs
The queen has the capacity to lay both fertilized or unfertilized eggs. She need only mate one time to lay eggs for the rest of her life. The queen ant's reproductive tract is equipped with a spermatheca where she can store the male sperm until needed. Fertilized eggs develop into sterile females that become workers, or winged alates that become queens. Unfertilized eggs develop into winged males. [Dolezal, "General Dissection of Female Ant Reproductive System and Brain]
New Colonies Started Through Budding
Some ant species do not leave the nest when it is time to mate such as the Argentine ant, the pharaoh ant, and the odorous house ant. These ants start new colonies by budding, that is, gathering up a few queens and workers and moving to another location. These ant groups are like gypsies moving from location to location when conditions are not favorable. ["Ant Information." University of Arizona]