We have 27 and they all do that. I also thought OMG my chicks are dying. Mine look like they are having spasms when they take their dust bathes. Really are some of the funniest things I have ever had. When the rooster lays over, with his feet sticking straight out believe me when I say, that is a sight to see. We have tan and red sex links, tetras, leghorns and they all do this.