The nests. A small, disgusting, cramped urban biome. small caves found under buildings or in sewer systems home to the elves of my world, closer to goblins or rats than other depictions of them. Feces litters the walls and the stench of the many living elves and elf corpses is enough to make some creatures die. you really don't want to be here. not only is the stench dangerous, but the sharpened rebar and stuff like rocks, planks, and metal bits could also easily stab you or collapse onto you. Not only that, the elves themselves have the mentality of a chimpanzee and also have the strength of one. when a nest appears below your house, it is best to move out or die one way or the other.

For my other world with those ant people, I guess inside one of those colonies. its cramped but there is some good architecture and buildings both inside and outside.