We occasionally see some out when gathering the eggs later at night and always let them back in but I'm sure some have spent the night outside as we don't check them every night. We have never lost any because of it.
I'm in MD also and we had chickens for 3 years without a door on the hen house and only an occasional hawk as a predator and we are in the country. On the 2nd night of putting our 2nd batch of young hens in with the mature hens, a raccoon raided the coop and killed 10 of the young hens. It was...