Place “No Trespassing” signs around the property. Take pictures. The idea is that the wannabe squatters will trespass and therefore break the law.
I saw my dad remove two squatters from his mothers rental 65 years ago. One came out through a second story window. The other kicked down the front steps and when he arrived at the bottom he had a 45 stuck in his ear with the warning to never return. Never forgot that or the two days it took to repair the damage they did.
Given how we coddle criminals these days my dad probably would be in a super max!
All they have to do to get around the law now is bring their crap into the house and use the address as their mailing address.
They also may start renting then quit paying rent later. Renters have far too many protections and the abusers know how to work the law.