That they do. Same goes for dust bathing spots. Apparently eanywhere except for the provided tub of sand is a great place to cleanse yourself. Our blueberries are having a hard time with all the chickens digging them up.
It's pretty common for them to pick a favorite box, and then everyone wants to use it, or so I've heard, we only have one laying yet, but she has a favorite box as well. Looking at the two others that are close to laying age, I might soon find out if they prefer the same one. You don't really...