When I get home my first task is normally to find where our Roomba has ended up. It can but rarely goes into a room and shuts the door behind it. Mostly it gets stuck on the back door mat. It can get onto it fine but can't get down again. It looks like the height sensors see it as too much of a drop so it wanders around the mat getting close the edge then going back. The plus side is the door mat gets very well vacuumed.