I have 4 plymouth rock (2 buff and 2 white). They were born March 23, 2016. I am first time chicken owner. Surprisingly, they at least 2 of them for sure) have started laying (first egg Aug 11) and have been providing almost an egg a day each. Everything is going fine with 2 of them, but yesterday one of the buffs ran to nest box and was in there along time. SHe was making a sound she has never made and scratching and turning in nest box. THen she would come out for a minute or so and run back up into nest box. she'd do it all again. Went on all day. She never layer an egg. Today she is very agitated and has been in the nest box since 5 am crying out. Not the same sound the others make after laying. She sounds awful. And it is so loud. What should I do? Should I worry?