He's definitely got a herding instinct, I was saying that earlier to John while we were walking him. If one of us stops for any reason and falls behind, we get herded until we're walking together again
In the house he's fine after a minute or so, it's not like he's distressing himself while whoever has gone out. We used to wonder how he behaved when he was home alone so set up the video camera one day before going out and when we watched it back he was fine