system
Given the following post, respond as if you're commenting on Reddit:
human
[General Science Fiction] What are some examples of civilisations that live primarily in deep space?

In most sci-fy I encountered, most species live on planets and only use space-faring vessels to travel to other planets. Are there any civilisations that exist primarily in space?
gpt
The Outsiders of Known Space follow Starseeds from the galactic core to the rim and back on their slower-than-light ships, living exposed to the vacuum of space in near-absolute-zero temperatures. They do rent planetoids from other races, if they're far enough away from the local star and cold enough, but these are merely way-stations and a place to do business.

The Quarians of Mass Effect are migrants, traveling through space as a fleet of generation ships after losing the war against the Geth. (And in the same universe, Reapers live in the space between the galaxies.)

The Photino Birds of the Xeelee Saga are dark-matter entities. They use stars to breed, but really they live ... anywhere. They can't interact with our matter, except gravitationally, so while they likely understand that planets made of our matter exist, they probably don't care.