How would you feel about me yelling at a guest for getting too comfortable in my house?
What would possess you to yell at them for that?
I can't stand visitors invading my house.
You shouldn't be rude to your guests. You can always talk to them like a civilized person and deal with it without any yelling.
Or I can just deal with it by calling the police.
That would likely be worse than yelling. You invited them in in the first place so if you think they've overstayed their welcome, calmly tell them so. Yelling may just make things worse and calling the police is way too extreme.