I let my girls out every evening for a few hours, but during the day when I check on them as I'm running errands or what not, they're just sitting there looking so bored. What sorts of things can I throw in there for entertainment? I do put some greens in on occasion. Do I just need to be more diligent about putting snacks in there for them to peck at? Or is this just the nature of a cooped up chicken?