Two of my six pullets are showing all the signs of getting ready to lay. I'm concerned that they will find a spot to do it somewhere besides a nest box, because they are free-ranging most of the day and I haven't seen any indication that they have been exploring the nest boxes. I have them well padded with hay, about 18" off the ground (so I don't have to bend over so far to get eggs) and a golf ball in 3 of the 4 boxes (as a hint). They have free access to the coop all day. Is there anything else I can do to ensure they know where to lay, or do I need to do anything?