Hubby is a Texan, I’m an Alaskan, where I come from we don’t have slithering ones, only 2 legged ones. Hubby told me, if the snake has a triangular head, watch out, it is not a friend of man. The copperheads I’ve beheaded had triangular heads.
If a venomous snake is not close to the house, I'll let it slide unless it behaves badly toward me, at which time it will meet Mr. 20 Gauge in a hurry. Copperheads, moccasins and rattlers have their function and I don't kill them for minding their own business, unless they are inside the fence where the dogs play.
Every time I've ever killed a snake just for the sake of killing it, I've (1) felt guilty; and (2)experienced some kind of negative snake encounter fairly soon thereafter.