I have 5 acres of uninproved land in Pa. can anyone claim this land for themselves? Under squatters rights?

Is there people using it for a long period ? Do you know they are there, have you chased them off.

Please supply the details.

There is no such thing anymore as squatters' rights. What you have to be concerned about is whether someone tries to take ownership of the land according to the law of adverse possession. In PA a person must use your land without your permission, preventing others from using it, for an uninterrupted period of 21 years before they can bring a lawsuit to declare them the owner.