I have three pullets that I think are going on 4 months. They are fully feathered and it sounds like their voices are starting to change from chirps to clucks a little bit. They are in a pen outside during the day and then I bring them into my shed at dusk. This is getting very demanding and would like to go ahead and introduce them to my roo so they can be in the run and coop with him but I don't want to if he may hurt them. A bit of history about him...he was in with my other roo and three hens who were all raised together until the beginning of January and I found the two roos fighting to the death. So I seperated them and now they each have their own coops. He hasn't been around other hens since then... I got these hens to put in with him and just need to know what the rule of thumb is for the ages of mixing hens with roos? thanks!