Hermit

Hermits are an alien species dwelling on a star in U* (U-star), a five-dimensional universe "above" the normal universe. They are solitary and non-spacefaring, but are in fact highly advanced.

Anatomy & Physiology
Hermits are large, shapeless creatures with a cavernous mouth and no limbs or eyes. They can extend up to twelve rods from their body, which they use as tactile organs. This is a three-dimensional approximation of their appearance created by human instruments, since their bodies are five-dimensional.

Biochemistry
Hermit biochemistry is based on a U* element known simply as atom 27, which is a rough analogue to carbon. Due to the bizarre properties of five-dimensional atoms, chemical and nuclear reactions take place in very similar conditions. Hence, Hermits require very hot conditions, like the surface of a star.

Diet
Hermits are slow-moving ambush predators. They feed on animals that pass by the openings of the caves they live in.

Reproduction & Life Cycle
It is unclear how Hermits reproduce or how long they live. Not one of Poincaré's six million Hermits were observed to reproduce or die during all the time humans spent there, implying that they live extremely long lives and reproduce very slowly.

Senses
Hermits are blind. They instead sense their environment by detecting heat, sensing their universe's analogue to infrared radiation. They communicate with each other by touching their rods together.

Homeworld
Hermits hail from a universe called the macrosphere or U*. This universe can be accessed through wormholes in subatomic particles in the normal universe. In some ways, the normal universe can be thought of as a single subatomic wormhole particle within U*, existing in a single point in space for a single point in time; however, creatinga stable wormhole between them synchronizes their flow of time. U* holds this same relation to U**, another three-dimensional universe, a pattern which repeats infinitely in both "directions."

In five-dimensional space, the inverse-square law is replaced by the inverse-fourth-power law. Because of this, U*'s laws of gravity do not allow for stable orbits. 90% of the matter there has collapsed into supermassive black holes, but much of what remains has formed into large star-like objects where both chemical and nuclear reactions take place. The inverse-fourth-power law also means that electrion clouds are confined to atomic nuclei, meaning that chemical and nuclear reactions can take place in similar conditions. On a visual level, the inverse-fourth-power law means that light dims much more rapidly with distance, making U* darker than three-dimensional universes.

The Hermits themselves inhabit a star called Poincaré by humans. Poincaré's surface is covered by magma-like oceans and vast crystalline continents bearing crystal trees and other forms of indigenous life. The star's hypersurface has a habitable area roughly ten billion times greater than Earth, although exact comparisons are difficult across dimensions.

Society
Hermits are as solitary as their name implies. They spend most of their time alone in their caves, usually emerging only to feed on passing animals. However, they sometimes leave their caves to wander Poincaré's surface. When they encounter other Hermits, they engage in communication by touching each other.

While they are solitary and have not developed spaceflight, they are actually very advanced. It is implied that they have engineered Poincaré to such a degree that the environment itself provides for their every conceivable need. They do not leave their homeworld simply because they see no need to do so.