Create a play area for your girls out of coated metal closet shelves. You can find them at Home Depot/Lowes type of stores. They love to climb them like ladders and they're so easy to wash down with a hose.
20 Boredom Buster Ideas-- CHICKEN CRACK BOTTLES Use a drill bit to drill holes in empty plastic bottles, add chicken scratch (aka: chicken crack) and watch the fun break out! Provide several bottles to the flock at once to avoid conflict & fowl penalties.