I have two female Muscovy ducks. One (White) is broody and sitting on her nest. She comes out once a day for food, water etc. The other female (Black) is not broody, she sleep outside and does not care. They are the same age. I also have one drake. The white female keep running off the black female when she comes out. She will also pull on her wings etc. I have uploaded a video. Does anyone know what is going on? Is the pen to small for both female ducks?