How the boys behave at the feast of meats? What comment is golding making?

 The boys are losing themselves in savagery and chaos. They snarl and dance wildly. Golding is making the point that, when given he state of human nature, these boys would naturally gravitate towards violence and chaos than responsible community members. Children must be taught through rewards and penalties how to be responsible. When left to their own devices, they will chose savagery.