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 intelligence

Depending ont eh child - a few never go through that stage, soem it is fleeting, some it lasts 8 years or so! (Humans, that is!)
@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.....