I'll stay out of there way and let them live if I'm in the woods, if they are near my house I'll kill them if they are poisonous. We have a strong copperhead population near my house and I have small kids that play outside a lot.
I usually stop and wait on them to pass far enough that I don't disturb them. I usually only see black snakes in my hunting areas. Now last year I was out doing some scouting and walked up a hill that was covered in thick ankle high vegetation and felt something moving under my feet. I looked down and there were what looked like 100 baby copper heads under my feet. It was probably only like 20 of them but, it scared the piss out of me. All I could do was high step it out of there. Luckily I had on good hunting boots and they were scattering as fast away as I was. All I could think about was a big one is somewhere and I don't want to find it. I don't think I've moved that fast in years!