A swarm box is used in the starting or first phase of the Doolittle method of raising queens. It is prepared by shaking in about 5 lb. of nurse bees from frames containing open brood. Pollen and nectar frames are provided and the grafted larvae are added a few hours later. The nurse bees start the cells, which are transferred in 24 hours to a finishing colony, and the nurse bees are transferred back to their hive. One well stocked swarm box will start about 100 queen cells.
The use of the swarm box is described in Successful Queen Rearing by Marla Spivak and in many other queen rearing texts.