i have no clue what to tell you. i can say that my older dog barks at any guy with long hair that approaches the car. it's always a bum asking for change. my wife and i will give each other the oh great face as he's approaching. the older dog must pick up on it 'cause she barks at every person that we feel undesirable on instinct. maybe everytime you come across a long haired guy it's you that's letting the dog unintentionally know to get this guy outta here just by your body language.