I will let @RebeccaBoyd elaborate, but i think it is a young rooster feeling his oats and trying to 'take charge' (the human, after all is iether the rooster - or treated like one by the other roosters. Note that Rebecca's boys will nap when she is there - or dust bath? She is taking on teh watch duties of a rooster and they can relax for a bit. But, not all do it, and most it is just their 'I'm growing up adn want to be the boss' stage - just liek human adolescents who suddenly become 'smart', then they grow up and return to normal intelligenceWhat is the charging thing all about? Telling the human to get away from his hens?

@RebeccaBoyd please confirm or deny my thoughts - based on observations....but I can be wrong - a very large flock have quite different dynamics than a smaller one.....and I am not as close to all my chooks are some of you are, due to my working f/t, ad part time job & having so many.....