My hens just started laying and was wondering why they take pieces of shavings, hay, a stray feather etc. and pick it up in their beaks and drop it onto their backs. They do this for a while after they have laid and egg and are just hanging out sitting on it. They could be doing it beforehand as well but I just don't notice it. They never just lay and egg and get up, they lay it and then sit there for at least a half hour arranging their nest. Any reason they do this? I hope its not something that has to do with them going broody, they just began laying last week. They are black sex links. Thanks.