@Mary830 If it were me, I might try putting in my listing that I require bookings to be overnight bookings and not hourly. Also, that anyone residing in the room needs to be a registered guest (meaning, you know their name and their age) for insurance purposes and for the Host Protection Guarantee to apply and that in certain circumstance you may ask to see guests' ID upon check-in (that might be a deterrant as some of the 'guests' might be reticent to offer up proof of their identity).
The last resort would be to only do 2-plus night minimum stays, as others have mentioned, but that could cost you some business and seems unfair to you (I remained sold out in the off-season by offering one night stays, for example, which is why I'm trying to come up with other routes for you to take to solve this dilemma).