A snake the size of this guy will not even attempt a grown bird...He or she might have a hard enough time in not being harassed by the birds. Enjoy having it around, you'll see less vermin in your coop, that's for sure :D
I think many people on the forum just dislike predators of any size or shape, and are going to tell you to watch your birds, your kids, your car, your dogs, kids, and for heavens sake, lock up the house since they might just move right in! Think about the size of that snakes head and the size of a fullgrown chicken...it (even with its tiny reptilian brain) will know it cannot swallow a whole chicken. I had pet snakes, and they'd refuse food if said food was much bigger than what they had been able to swallow easily before...I think you'll be fine.
Lol... that's true... and snakes have that fear factor. DB even slept with his feet tucked securely last night.
Feeling somewhat better again, and I would agree that they would go for an easier target. Which there are plenty of! Crawling with gophers and ground squirrels this time of year, and the tree it had slithered up is a notorious rat highway. Yes, little tiny head compared to body girth, and even with unhinged jaws I'd figure a tennis ball would be tough. I'll keep an eye out, though, and if I see it near the coop again (which it very much was), I'll try to relocate him into the hills behind me.