I bought three ducks out of the mixed bin at TSC. A pekin, a khaki cambell (I think), and Scooter (middle in picture). Scooter was a bit smaller than the other two, and now he's half their size a week later. He doesn't seem distressed, but sits on his bum all the time (doesn't stand to eat, he sits.) He tends to scoot rather than walk when we have him out for play time on the towel, but he can run short distances when spooked. What gives? I don't notice any obvious malformation??? Is this normal?????