Snakes such as this fine blacksnake prey on rodents and insects. I have rarely found them to be a problem in the henhouse as long as I don’t feed free-choice inside the coop (or better, feed outside the henhouse entirely), since mice who multiply by free-loading on your feed tend to draw snakes. Once inside the coop, snakes will eat both eggs and chicks. Another deterrent: Keep the floor clear of clutter so snakes have no place to hide. If you suspect that a snake may already be preying on your chicks, however, putting down something on the litter (e.g. a large scrap of plywood) may be just the strategy to lure the snake to shelter underneath. Lift the cover periodically until the snake has hidden there, then you can catch your snake.