We get brutally cold winters here and would like to put our guinea's in a pen in the barn for winter. They free range with the chickens and occasionally sleep in the chicken coop at night, though usually they just roost on top of the chicken run. Once the chickens are closed up for winter the guineas will be locked outside (not enough room to keep them enclosed with the chickens). The pen in the barn is 7' x 10' with a 10' or 12' ceiling. How many adult guineas can be kept in a pen that size and what would be the best male/female ratio?