My 8 week old BLRW roo that I plan to keep has been getting aggressive this past week. He has started running at me when I open the coop and puffing his chest up at me. He then proceeds to try and bite me, aggressively. He nailed me once hard enough that I lost my temper and grabbed him by the neck until he calmed down and then I let him go. What else can I do to teach him I am not a threat and calm him down? These were all hand raised chicks and all will eat out of my hand and are fairly tame. This roo in particulr is my prettiest BLRW roo, so I don't want to get rid of him unless I have to. Thanks!