My understanding is that Black snakes keep Copperheads away, so with that in mind, they don't look all that bad to me. But I'm not exactly thrilled when I have to "do" things with them. It's hard to get a 5' snake on a shovel....
I've had black snakes in the coop several times. I kept finding dead chickens that looked healthy. I think they were getting suffocated but were too big to swallow. Then chicks started disappearing. It suddenly dawned on me that there had been a snake in the coop. As I was inside the coop...