I've only had chickens (and one Japanese Blacktail rooster) for about a month. My rooster is only about six months old and has started trying to "mate" with every other chicken in the hen house. I have 8 hens and 5 of them are WAY bigger than him. I've only seen him mount the big hens. Is it possible for him to mate with them...he's pretty small, but he's trying hard!?!