I look at this as an arena of ideas. We discuss ideas, and opinions. I'm brand new at this, and while I'm not fearful of snakes, in general, I'm not fond of them either. Do they have redeeming qualities? Sure. But so do skunks, opossums and politicians.
I'm not advocating it, as I haven't even put my chickens in the coop yet. My weld wire fence, around the pen/run area, with 1.5"x3" openings, is still a bit open for the bantam chicks, and certainly big enough for a snake to get through. A dog run, around the pen, should keep out the mammal critters, but a snake could easily slip in. I'm open to all suggestions, and only mentioned this one, that I've been told of, so far, for perusal. But, I must admit, that I don't get heart broken, when my dog hunts and captures a lizard, torturing it to death. And, I would not feel terrible, about the death, regardless how gruesome it may be, of a snake, be it viper, or not. They leave me, and mine alone, and I leave them alone. Mess with my flock, or pack, and I will hunt you down and kill you, if I can, whether you are a 1' bull snake, or a large cottonmouth or copperhead. Sorry, in my opinion, on my land, the only good snake, is a dead one.