I have observed our chickens going nuts over a small patch of wet ground. They all roll in it and sit in it. I have seen them do the same thing with dust, but they seem to prefer a little mud now and then. A quick internet search tells me this is to take care of tiny parasites. Should I throw in a cup or two of water every day or several times a week?
Our chickens live in an 8'x28' coop.