formed, communication between the original colony and the new bivouacs will cease. Queen behaviour Being the largest ants on Earth, army ants, such as African Dorylus queens have the greatest reproductive potential among insects, with an egg-laying capacity of several million per month. Army ant queens never have to leave the protection of the colony, where they mate with foreign incoming males which disperse on nuptial flights. The exact mating behaviour of the army ant queen is still unknown, but observations seem to imply that queens may be fertilized by multiple males. Due to the queen's large reproductive potential, a colony of army ants can be descended from a single queen. When the queen ant dies, there is no replacement and army ants cannot rear emergency queens. Most of the time, if the queen dies, the colony will likely die too. Queen loss can occur due to accidents during emigrations, predator attack, old age or illness. However, there are possibilities to avoid colony death. When a colony loses its queen, the worker ants will usually fuse with another colony that has a queen, within a few days. Sometimes, the workers will backtrack along the paths of prior emigrations to search for a queen that has been lost or merge with a sister colony. By merging with a related colony, the workers would increase their overall inclusive fitness. The workers that merge into a new colony may cause the colony to increase in size by 50%. Sexual selection by workers Workers in army ant species have a unique role in selecting both the queen and the male mate. When the queens emerge, the workers in the colony will form two 'systems' or arms in opposite directions. These queens that are hatched will move down either of the arms and only two queens will succeed, one for each branch. Any remaining new queens will be left in the middle and are abandoned. Two new bivouacs will be formed and break off into different directions. The workers will surround the two to-be queens to ensure they survive. These workers that surround the queens are affected by the CHC (pheromone) profile emitted by the new queen. When males hatch from their brood, they will fly off to find a mate. For males to access the queen and mate, they must run through the workers in the colony. Males that are favoured are superficially similar