Originally posted by abledfire:

Found a way to increase the number of animals in a pen to however many I want. I did this using the medium pen for sheep. First, make one, fill it with sheep. Then make another medium pen and move the sheep to the new pen. For some reason the sheep being moved don't count and get bugged by standing in a corner trying to get back to the old pen. Kill the sheep, you now have -6/6 sheep, and can now hold 12 sheep!