What do you think about aliens?

[Gawdzilla Sama]

If in fact brute colonization via interstellar emigration is not a major step in the development of interstellar civilization, then that means the cost of interstellar expansion would be much lower than we imagined. It also means the incentive to forcibly convert somewhat unsuitable candidate systems for expansion would be much less because the value of keeping expansion in a compact consolidated mass would be less. This could provide a explanation for why even if we are surrounded by interstellar civilizations, they may have no reason to comport themselves in ways that would reveal themselves to us.

Or they're Moties.