Our neighbour got a new puppy about 3 weeks ago. We hear it barking constantly through the walls if it is left alone. This has happened at night when they tried shutting it in one of the bedrooms (at least I assume that was what occurred as it was barking constantly in the bedroom next to ours and the stopped when it sounded like the owner came and got it from the room). It now happens in the daytime when I assume it is now being left alone in the house as there is no other noise coming through the walls apart from the barking dog. I wondered if this is normal for a new puppy as they are unused to being left alone? Is it a phase that most puppies go through when first left alone by their owner and do they quickly adapt and become calmer when left alone?