You probably just don't have a guard dog on your hands. Some dogs are guard dogs naturally and some aren't. My dog is. Woe betide someone that tries to break into my house in the middle of the night, or perhaps not since at the moment in my current living situation(I just moved in) the dogs are still getting used to each other and my dog spends most of her time in my room. But woe betide anyone that tries to break into my room and rape me, and I'm 100% sure my roommates dog would take care of anyone trying to get into the house, he's quite a good guard dog as well, really too aggressive w/ it, he would bite first ask questions later if a big man he doesn't know simply walks in the door, while I'm quite sure my dog wouldn't bite unless someone was truly breaking and entering in the middle of the night.