My "No Girls Allowed" flock shares a run wall with the main flock. Other than some posturing through the hardware cloth, there are no issues between the two groups. I've had as few as three and as many as nine in there at once (make sure you have enough space for them and lots of things to hide behind - not just under, but behind. I LOVE my Bachelor Flock - The eye candy and the antics are well worth the added effort of separate digs and feeders. I call them my "Frat Boys," and they're my FAVORITE flock!