I have 10 15-week olds. One of the barred rocks is much more mature (has more comb and waddle) and I'm thinking she may be the first to start laying. Is there any way to tell when she's ready? I have 2 that are pooping in the nesting boxes still - I've got to get them to stop! I may try hanging a covering with slits over the front of the boxes so they aren't as tempted to roost in there. Thanks!