Edited by jkrollins - 9/26/15 at 10:48am
Bugs in nesting box.
Look like Pillbugs, Sowbugs, RollyPolly bugs?
Here's link with description : http://www.floridiannature.com/creepycrawlyinsects.htm
All I have ever seen are the Rolly Polly AKA Doodle bugs.
Not that I know of, but bet the chickens are a problem for those bugs.
But I have never seen those inside a structure, just outside around them in sand or dirt. But read if you have a really large infestation, then they come in.