"Gardening books often talk about the need to turn the contents of a compost bin over two or three times during the composting process to aid the breakdown of the organic matter. However most gardeners rarely turn their compost bins, which often results in compost of an uneven quality. But if chickens are allowed access to your compost bins they will turn them over hundreds of times during the composting process as they scratch for worms and other food. By doing this they make a wonderfully fine compost as even course woody material is literally torn apart by their actions. Not only do the chickens help break down organic matter they also remove virtually all weed seeds in the material. And as they scratch they also add their chicken manure, which is an excellent fertilize."
Wow! I wish I'd seen this before. I always try to keep my chickens out since when they "forage" in the pile, they send stuff flying all over the place. I suppose if your pile was well contained you could let the chickens in. I always thought they'd gobble up all the good worms too. One thing I do get is big, fat, one inch grubs (japanese beetles?) and I collect them when I turn my pile and the chickens get a good feast! I cover mine with tarp to keep the chickens out...
I'm not sure...if a compost pile is working properly, it won't have anything in it to attract the chickens. Certainly not worms. And chicken droppings are really 'hot'--high nitrogen--, so it would add to the length of time your pile must be composted.
My free range chickens do lots of digging in the kitchen scraps from our kitchen and the one where I work. They and the dogs eat what they want then the rest rots into the soil to build it. No meat scraps left to worry about. But chickens will be hard on the worm population.
I use lots of poultry netting(wire), usually the 30" tall kind. Sometimes I lay the netting down flat and let the plants grow thru it. The poultry(chickens, ducks, geese, 1 each guinea fowl and Peacock, can peck and eat the foliage but can't scratch in the dirt thru the wire.
I don't find chckens hard on worm populations and mine (in the past) were allowed in the compost that was kept in their enclosure, and then in the garden beds from end harvest till early spring. Little to no weed problems and great soil. Yes they do get some worms, but that's only a part of their diet. Since they give back so much, it isn't a concern-the worms seemed to thrive anyway.