They do have an odd smell. Rodents & Red ants smell, too. Groundhog poop is very nasty. All are stinky!Our place is lined and up the walls with 1/2 inch welded wire. The mice fly through it no problem.
The snake has moved on to the barn. I no longer smell it in the coop, but I do in the barn. He can eat all the ground squirrels and mice he wants. I don't mind snakes. They just smell.