When the first workers emerge they are very small and timid, compared to the later generations of ant that will follow. They immediately begin to expand the nest, tend to the queen and brood, and eventually remove the seal from the chamber entrance created by the queen, and forage above ground for food. This is a critical time for the new colony as food will need to be gathered quickly in order to feed the near starved queen, who would have lost about 50% of her body weight, and to provide her with the nourishment needed to create more eggs. From this point on the queen will cease all other functions, but will instead become an egg laying machine.
As future generations of ants are produced, they will be bigger, stronger, and more aggressive than their older sisters. After a year or so the colony will enter an exponential stage in growth when the population will rise dramatically. Once the colony is well established, which can take a couple of years or more, the queen will start to lay eggs that will turn into winged males, and later on, when the colony resources are plentiful, large winged queens will appear, and the whole cycle is started again.
There are several other methods that ants use to create a new colony. Some of the polygyne ((more than one parent queen) species will be created by several queens who come together to start a new nest. Unlike a group of cooperating Lasius niger queens, Myrmica rubra queens will continue with several queens after the first batch of workers are eclosed, and will continue to function as a single colony with each queen contributing to the egg production of the colony.
"Budding" is another method in which new ant colonies are created. An example of this is shown in the southern red wood ant Formica rufa. These ants can have over one hundred egg laying queens in each colony, and once a colony becomes large enough, one of more of these queens may leave the nest, taking hundreds, or thousands of workers and brood with her. They will found a new colony, usually not far from the parent nest.
Parasitism is another method by which newly mated queens of the species Formica sanguinea, the largest of the native British ants, may create a new colony. A newly mated queen will force her way into the nest of a smaller species, such as Formica fusca and snatch some of the brood. She will then created a sub-cell within the nest and defend it against the colony's workers or queens. The queen may kill the parent queens herself, or she may wait until the brood she has snatched emerge, and they will associate themselves with the sanguinea queen, and kill the original queen themselves.
Lasius umbratus queens uses Lasius niger nests to create their new colonies. They will enter the Lasius niger colonies, acting submissive to any niger workers they meet, in an attempt to avoid combat. Eventually the umbratus queen is accepted by the niger workers as their own, and they will kill their original parent queen.