I have an Australorp that I got in late June at four months old (so she's now about 7 1/2 months old). She has never taken to roosting like her sister--every night I find her sitting on our golf ball (fake egg) on the floor of the coop. She reluctantly allows me to put her on the roost when I bother. A few weeks ago I noticed her breastbone is bare. The weather was turning cooler, so I thought maybe she was molting in an odd way, but she's still laying almost every day and the bare patch is unchanged. I recently figured out that she is deliberately sitting on the golf ball--she moves it to get it under her when she goes into the coop at night. She spends more time than the others hanging out with the golf ball--but nothing like all day. She forages with the other girls most of the day. I find no other signs of illness, and the other girls have no bare patches. Thoughts? What do you think is going on with her? Is she an ambivalent broody? Or is something wrong with her?