My 3 chickens are free-range in our fully fenced in back yard.; and always come into the coop and put themselves to bed around 5:30. One would stay out a bit later than the others, but always in by 7:00 p.m. Last night she disappear in the late afternoon and out all night. She came back in the morning and we kept all the chickens in the enclosed coop/pen until I was able to watch them this afternoon. Sure enough, she hung out with the other girls until I went in the house to get them fresh water, and now she is gone again. No amount of calling or shaking the scratch can will get her to come out of hiding. she started laying eggs a couple of weeks ago, but only laid about 1 each week. Last night when we looked for her, we found an egg in an impossibly small space between some rocks. We blocked it up and saw her try to go in there this afternoon, but she couldn't fit. So -- does she need to go to chicken jail for a couple of days???? All afternoon she didn't act like she wanted to go hide and sit on any eggs in a hidden nest -- ate a snack with her friends, took a leisurely dust bath and laid in the sun for a while.