So, Aliens...

[eberetta1]

But back on topic:
Aliens have buttholes. ebretta, if you want to suggest there are aliens without buttholes I am on the edge of my seat waiting for your idea how that contraption would evolve. And would it not spend a long time walking across the fields wondering why it kept getting larger.

My comment was not concerning holios. My comment was ... An advanced lifeform is able to float right thru walls, so a species may have no need for doors.