Well, I'll be! My most skittish BO did that very thing just this morning. I came in and told my husband, "It's like Hazel's had a complete personality change. When I walk up to her she just hunkers down and lets me scoop her up. Plus, her wattles and comb are getting really red. And ditto for Lucy."
I had no idea that was an indication of egg laying. I thought it was conditioned behavior, anticipation of being picked up. Out big girl and first to lay eggs always does it, our ornery Sussex is a regular layer but never squats. Such curious behavior!