A couple of months ago I tried to co-mingle two different flocks, the resuts were bad. The older hens killed two pullets. I seperated them with a barrier where they could see each other. This week I tried to put them together again, this time they have hurt the rooster of the younger flock. Older flock of 12, 8 month old Barred Rock Hens, Younger flock 11, 4 month old Buff Orf. I can't keep them seperated forever....................can I, or will I have to.