Being that they originate outside of our solar system (At least according to me), and had to have solved the problem of travel between solar systems (being that the closest star to us besides the Sun is 4.37 light-years away) somehow, it would be nothing just for them to dart to Earth from Sedna (Takes 11,400 years for Sedna to orbit the Sun).
I think that the distant dwarf planets would make very good hiding places. I’m not saying this is where all their bases are by any means.
But then again, maybe they just leave back to their home or a colony after completing an objective?
Also, this is my first post here. I’m new to this community in general, UFOology and alien theory and such.