I normally let my six chickies out of the brooder to "scratch" for crumbles a couple times a day (in the house, still too chilly out). They are three weeks old now. Tonight, when they were on a piece of carpet I use with them (so they don't soil the regular carpeting), one of them started scratching like normal. All of a sudden, she started a belly crawl, while still scratching. Then she laid down completely occaisionally scratching and continuing pecking at the crumbles. I thought something was wrong, but all of a sudden, three more did the same thing. I wasn't sure if they were dusting (because they're feathers were all fluffed out, or this was an attempt at nesting? It seems like normal behavior, because once the first one did it, others followed suit.