They know.
Please don't think that hiding your RV is going to protect you from burglary. Most burglaries are committed by teenage males who live within a one mile distance.
They know you're gone because their best buddy Joe is the son of your neighbors. Joe's parents mention your vacation while Joe and his buddy are at the house. Later, buddy casually asks Joe "so what house do those friends of your parents live in". Joe tells him. You come home to a burglarized home.
If you really want to prevent burglary while you're on vacation, get a housesitter. If you can't get someone to stay, then ask several friends to stop by during the day (*).
*Most home burglaries are done during the day while adults are at work (and teenage males are hanging around bored).
