Lock the dog door.
Otherwise, you may wake up early and decide to walk through your living room and narrowly avoid stepping on the carcass of a murdered possum. Because, of course. Why wouldn't my dog go out in the middle of the night and kill a possum to bring back for me as a gift? Silver lining: I'd rather have a dead possum than a live one in my living room.
Be glad I decided to draw the line at what is Instagram-worthy. No corpses.