Mine didn't start squatting until 25-27 weeks...then started laying about 1-1 1/2 weeks after that. Easy way to tell is to walk up behind one of them and reach down like you plan to pet their back. They'll either run away...thinking you are a lunatic...or they will be compelled to squat down like you are a rooster trying to mate them.
They suddenly freeze in place (making it very easy to catch them if you need to), lower their body a bit and spread their wings out partway (not full extension). Sometimes they just do that for a second, and sometimes they will freeze and not move for a few minutes..even if I prod them with the toe of my shoe. (Crazy chickens!). It's quite a sight to behold.
My poor husband, who is supportive of my chickens but a bit freaked out by them, had to try and get them to go back into the run by himself the other day and he called me at work saying, "every time I shoo them toward the run, they freeze, look at me funny and lift their wings". I told him that meant they wanted him to be their rooster. I don't think he was amused!
