The rooster and hens usually get along fine all day. BUT, first thing in the morning is a different story. When I open the coop up (which opens into their 12 x 12 pen), the rooster comes out first. As soon as the next hen comes out, he attacks - chasing her all around the pen. When the next one comes out, he does the same thing! This is the only time he's very aggressive with them. Any thoughts? I'd love to know why he does this!