Sometimes this is carried back to the nest, but more often it is ingested where it is found. Later it is regurgitated in the nest for use by the queen, developing larvae, and non-foraging workers. Under optimum conditions it takes about 3 months each for egg, larval and pupae stages. However, colder weather may lengthen this period to as long as 10 months. They open the chamber to the outside, collect food, excavate galleries to enlarge the nest, and tend the eggs, larvae, and pupae of the second generation.
Workers regurgitate food to nourish the developing larvae.
The queen, fed in the same manner, has few, if any duties except to lay eggs. If conditions are favorable, the size of the colony increases rapidly in the next few years. The colony is considered mature when winged reproductive are formed. This occurs in three to six years when the colony contains 10,000 to 12,000 individuals or more. It is unlikely that numbers will increase thereafter, due to the constant drain of the many warmers produced each year.