Vampires
Day walking vampires have always thought there isn't any issue with simply being as a human society would be, but they're not confined to night hours. They can better assimilate. They can better blend. That is unfortunately not the case with the vast majority of us.
The only rules I'm currently going to propose are that we keep a wary eye on population in areas, that we do not make or destroy our own kind. there should be only one of us to every ten thousand humans in each area, to ensure the safety of our kind. It's common sense to most, but you'd be surprised how little common sense matters to some.