My 4 Sebies have a 12x12 horse stalll at night with access to it during the day. They also have a yard off of the stall that is maybe 30x48. I was thinking of putting a large dog house in one corner of the stall. Will they like that for a nest box?? I am not sure how many nest boxes I need. Will they share?? I don't know who is a girl and who is a boy.