Since I have researched Dayton the most - I'll start with them:
In the Dayton municipal code section 91.01 it says "Pet means an animal that has been adapted or tamed to live in intimate association with or for the pleasure or advantage of people and includes, but is not limited to dogs, cats, birds, rabbits, and hamsters. Pet does not mean any animal purposely kept as food." This is one point of contention that I had with the city staff. I believe a few laying hens would be pets, not food. I don't plan to kill them once they stop laying eggs and that makes them pets in my book. What I heard from the staff is that since you are harvesting something from the animal it isn't a pet in their book. I disagree.
In municipal code section 91.02 part (4) it says you may not:
"Keep animals other than cattle, poultry or fowl, swine, sheep, or goats in an enclosure without wholesome exercise and change of air, nor feed cows on food that produces impure or unwholesome milk." BTW - I interpret this as permission to keep chickens in pens but they want them to be fed wholesome food and get fresh air.
Similar to the state law; it says in Sec. 91.04 that you can not sell baby chicks less than 3 weeks of age in lots of less than 6 chicks. In the municipal code in section 91.20 it also says you can not let a herd of animals run in the street including chickens. But, if they find you running after your chickens - they won't impound them! The imagery I have of chicken fanciers chasing chickens down their blocks all over Dayton - makes me laugh =)!
In section 94.05 (E) You can not have animals or birds that make long or enumerated noises such that it would disturb your neighbor. Since in my experience a few hens are less noisy than spring robins, I think we can meet this requirement.
You can check out the code for yourself, here: http://library.municode.com/index.aspx?clientId=13723&stateId=35&stateName=Ohio
My suggestion to city staff is to allow hens only; clean pens weekly; dispose of waste in trash or compost piles; keep feed free of rodents; if requested, don't place pens near property lines; register and pay a fee, NO ROOSTERS (they could be construed as noise nuisances anyway) and in any other way accommodate the locavores who love the City and want to also raise chickens here.
The city staff also recently made a push to allow bees, community gardens, compost, and more pop-up farmer's markets in the zoning code. While I appreciated those changes, clarifying the zoning code to allow registered chickens really seems like the more responsible way of doing things than telling folks to just do it in secret.
So I'm on a mission to root out the specifics in other localities. I've heard Kettering is a no (but I have no personal knowledge). I called Harrison Township and since the link on their web page was down when I tried to access the law; I talked with someone in community development or zoning department. He seemed to think it was a no: and no, no one in their township wanted chickens. They would be way too dirty and noisy. I began to argue when I realized I don't live there - and never will, if they don't get more friendly.
BUT the first time I called Dayton about chickens I got the same info. Until I looked more closely for myself at the law. So, if you live in another locality, PLEASE, PLEASE - research your law. Don't take their word for it. Call the City staff, and, with the details in front of you, negotiate. Then post here about your progress.
Together, we can make this happen!