Document to avoid Squatters

[Cat R.]

I have been hearing about squaters and how they can mess things up for a landlord/owner. How can we prevent that or how has someone successfully got them out of their homes? Someone mentioned creating a notarized doc stating that after 30 days If the rent isnt paid I‘m allowed to toss their belongings out and kick them out...both of us sign and notarize it...can they still squat?