We shut ours in every night (they'll put themselves to 'bed' but we secure the door). They have a nesting box as part of the coop that I put straw on. They lay in their nesting box. You can get away with any kind of box that has some straw in it, really. If they don't like it, you'll find eggs laid in various plants in the garden! Our yard is fenced, they chase away the cat from the neighbour, but I haven't seen any snakes yet, so can't comment on that. Big goannas are also a bit of a terror to chickens.