I'm on board with the dog idea but I see no problem with a terrier. All I want from my dogs is to tell me when someone is there. I do not expect them to go fight off a bg, call the cops, or defend the house in general, that is my job. I don't require them to defend the house when we are away, that is what the real alarm system is for. Anyone who is up to no good hates a house with dogs, not just big dogs. If someone wants in your house so badly they will more than likely be able to get past a dog one way or another. My dogs just make sure I know a bg coming.