We have a two part security system, the little dog and the big dog. Or, to continue with the nom de blog approach, we will call them the Barker and the Bruiser.
Between them they make enough noise that we know if anything funny is going on. And when someone arrives at the top of the drive, they are met with enough sound and fury to keep any sane person in their car until we call them off.
Just what we want.
They are good, good dogs, and are really enjoying themselves out here.