I had a texas rat snake eat 4 of my 2 week old gunieas. now have built 2 8x8 chick houses. I put electric wire all the way around 4 inches off ground plus I bought some flower garden edging the rubber kind layed it on the groung staked down with #16 nails with 2 wires 2 inches apart atached with wire ties 24 inches apart. this will stop the snakes just make sure they can't crawl under it anywhere. wire is only turned on after chicks are in house after dark turned off before letting them out in morning.
That should stop predators but not sure for snakes. Bird netting loosely rolled up and layed around your pen will catch snakes for sure though.
