I caught a 10" copperhead in a sticky trap in the kitchen about 15 years ago. I had a guy go under the house, and mouse proof it, which also snake proofs it. In theory. If I caught a 3 footer in the house and Linda found out, I'd have to buy a new house.
Since I got the Jack Russell about 10 or 12 years ago, I have seen one snake on my place, and he didn't last long.