I have often heard that humans give off a different scent (from behind the ears) that dogs can sence when you are fearful. Not sure how Buddy would react as he is really not a barker or gets worked up about anything. But one time my husband came home sick (he was working nights then) about 3 am and Buddy did not hear him pull in the driveway and when he was unlocking the door Buddy really gave out a loud deep growl !! Otherwise he loves about everybody that comes to the door. So I don't know but I think I feel safe with Buddy around.