This is a very interesting question. It is Jackson's genius that she would be painstaking in describing the children's reaction to the lottery tradition. She opens with talking about the freedom of the children and capturing the spirit of innocence of the children in the village. Being able to talk about how they are stacking the rocks and excited about the recent end of school is reflective of this. The stacking of rocks is significant because one thinks that this is innocent and simple as opposed to act of proactive aggression. It is this dualism that is struck in the children's actions in the story. When Tessie's family is called up to redraw, the support for the daughter is heard when one of the children express the wish that she is not the chosen one. When someone gives little Davey Hutchinson stones to use against his mother, it is a significant moment that reflects how the children's actions walk that line between being children, but also being agents of this horrific tradition of violence present in the town. I think that being able to raise the issue of the children in such light is Jackson's way of suggesting that a culture of violence is one that permeates childhood, as well.