What role do the children play in the ritual?

From the text:

Bobby Martin had already stuffed his pockets full of stones, and the other boys soon followed his example, selecting the smoothest and roundest stones; Bobby and Harry Jones and Dickie Delacroix-- the villagers pronounced this name "Dellacroy"--eventually made a great pile of stones in one corner of the square and guarded it against the raids of the other boys. The girls stood aside, talking among themselves, looking over their shoulders at rolled in the dust or clung to the hands of their older brothers or sisters.