We have a bale of straw in our run (left the wire on that is holding it together) and they jump on it, peck it, and scratch it. I turn it every week or two and they come running for all the bugs that congregate on/ under it. They never tire of it, and when they have pretty much shredded it, I take the wire off and they scratch it everywhere. It lasts a long time.
i know birds needs stimulation, especially caged birds.. but i also wonder if free range chickens needs toys and games.. or if they get enough scratching for bugs and such.. i know they "play" with me.. they peck at my toe nails [especially if i am wearing red polish] they peck at my buttons or snaps even pull my hair.. of course i think it is more food related instincts than play..
interested to see what other more experienced chicken owners find.. and possibly different breeds need more or less..