If my ducks/chickens/geese see a big blk snake they usually just move away from it. We did have a 6 footer in our coop last year and one of my ducks decided to take it on since she was brooding, I am glad I went in and got the snake out I don't think she was making any progress on scaring it off. Had another one about 3' actually get one of my day old ducklings last year and I'm not sure if mom tried to intervene since when I found it the snake had pulled it through the fence. I took care of that one, duckling lived too.What about the big ones ;-(