My Aussie and Newf yes i need a leash,but my Border Collie Maggy no i bring her leash but she stays at my side if i see someone coming i put her on "Just in Case" we have always said about Maggy we could leave for a couple days and she would still be in the same spot when we returned she is so smart when it comes to knowing boundries and no training has gone into this dog.They say though you never will have the same i dont know all my border collies have all been smart...that is why i love the breed.