I've had hen's lay in odd places many times sometime in the run other times on the floor of the coop
even had them lay while they slept the egg dropped but didnt break.
I have 12 nesting boxes and 9 times out of 10 every hen chooses that one box lol who knows why?
chickens are silly lil critters
The coop is open all day, they come and go as they please. And mine both lay in the same nest all the time until i put some fake eggs in the other nest then they laid in that one. I guess they are gonna lay where ever the urge hits.
I think they do this sometimes because they don't realize it's an egg. I've usually had old hens or very young hens do this, however nothing is etched in stone.
About 3 weeks ago I opened the coop door and was watching everyone mingle and fight etc. I was tossing some scratch and I leaned into the coop to toss some to my big rooster Hamish (went blind in one eye after the big rooster fights this Spring), he tends to hang back and eat last when everyone leaves the coop. Well, there were a few hens hanging in the coop, one was nesting in a box and then other was watching her. I noticed "Ditsy" a RIR hen up on the roost, her neck was pulled down and her wings were out to her side, she had a very weird look on her face. Well I thought she was sick, she looked like hell. As I was watching she started to moan!! And then, plop, the egg popped out!!! Her head popped up, wings in and she hopped off the roost. I really thought she was ill, and I had a good laugh at myself after I saw what happened. She went over and shared Hamish's scratch and was fine and dandy.