I have a year old APB/Rotti mix. He is fully house trained and hasn't had but minor problems for a long time. Normally he cues us to him needing to go out by running up to us, barking, and running to the back door. Recently though, he's gotten to where he won't interrupt us if we are in conversation to let us know he needs out. Instead he'll go into another room, but stay in sight and "dribble" and then come back and stand in front of us and stare at the spot untill we ask him if he needs out. My question is, How can I train him to interrupt us when he needs to go out.