I have a bird feeder, looks like a double topped shepherds hook with two pieces of chain with a shank hook at the ends. I put cabbage and cauliflower leaves onto a piece of galvanised wire so it looks like a cabbagy Christmas wreath and hang this from the ends of the chain. It swings and twirls and keeps the hens amused for hours.
Also there is a product called Peck a Block. It's solid seeds in a block and it takes them ages to demolish. I personally don't use them as they are too expensive for 40 odd hens but make my own.
Give them lots of greens and even your pumpkin from Halloween to peck at, they love the flesh, seeds, in fact all of it apart from the skin.