My 21 week old Barred Rock, Stella, has been doing something very odd... she will suddenly squat down, tense up, and hold her wings aloof. My Rhode Island red, Lucy, (at least we think it's her, she's got the largest and floppy-ist comb) began laying last weekend, and we never saw her do this kind of behavior... so I don't think it's just Stella getting ready to lay. Could she have an impacted egg? Could something else be wrong? Please let me know! I'm a little worried about my Stella.