We have 6 -- all 21 weeks and two are laying. With our first layer (an Ameracauna/EE who started at 19 weeks), it was the squat that was the sign -- she was the first to do it and started about a week before she started laying. But she has a tiny pea comb and almost no wattle, so that wasn't a good sign. She did a lot of nesting for a few days before too and got really ticked off if any of the others came near her when she was in the box. With the second (a Gold-laced Wyandotte who started at 21 weeks) it was the comb and wattle -- hers is the reddest and largest -- but she doesn't squat for me at all and showed no interest in the nesting boxes until the day she laid her first egg -- and kicked up a huge fuss about it. It was a total shock to me that she was second. Of our other four who haven't started laying, the Buff Orpingtons are squatting, have good sized combs, but they're pink still and not very red -- but they're constantly in and out of the boxes. I think they may be next. The RIR just squatted for the first time today but her comb is only medium red and I don't think she's ready. The Partridge Rock is the biggest, has a good size wattle and comb, doesn't really squat but is pretty interested in the boxes.
So, I think the real message is -- they're all heading in that direction, some time between now and a month or so will start laying, and you may notice behaviors and physical changes before they start laying. Or not! Frankly, I don't know what I'll have to obsess over once all of mine start laying!
