People that turn up at your door and lightly tap on the door (They're on video). When there is a ring door bell that you can't miss next to the door. It has a light on it, it stands out. But for some people they just ignore pressing the button. Then mark down on their paperwork that there was no answer and move on to the next house. Same with delivery drivers. Why can't they press the damn doorbell??? Feckwits...