head swaying roo

I have a 6 month old super sweet Dominique rooster. He has just now become the main man and is learning all of the rooster duties. Just recently he has started swaying his head every once in a while. It is like a quick left to right motion when one of the hens is doing something he doesn't like or when he is nervous. Is this normal? I read on the forum that this could be a problem with the crop or possible worms. The chickens are free range and he has opportunities to eat whatever he can find on the land and in the garden. I felt his crop and it seems normal. He is eating fine, drinking and his poop is solid. This is my first flock, am I making more out of this than needs to be? Is it just a rooster thing like the foot stomping or do I have a bigger problem?
Help! I can't find any info on rooster behavior.