Best way to describe it! So, a year ago we got 4 Pekins. One male ended up being "different"; he never fully developed a quack, has a line like a split down his chest, and the 3 others we got at the same time leave him out often. Yesterday, my son and I were laughing as he was alone in the pool spinning in circles - around and around - super fast, then bumper boating his body off the sides. Today when I let him out of pen, it looked like his head was swaying and bobbing. Ever so slightly, but enough where I noticed. Is this a "thing"?