I own 3 acres of property which i do not live on, but maintain taxes on. currently there are two trailers on the property owned by other people. I have allowed them to live there rent free as long as they maintain the property(i.e. keep the grass cut, don't trash the place, etc.) Is there any possibility of these people claiming adverse posession on my property in the future? one has been there approx. 5 years, the other just over a year.