Rachni

The **rachni** are an insectoid race of sapient beings with highly aggressive tendencies. The initial contact between the rachni and the Citadel Council changed the course of history in the Milky Way.

## Physiology

The rachni operate in hives commanded by a single mind. Within each hive, several subtypes of rachni serve various purposes.

* Rachni Queens - these large and intelligent rachni lead each hive, providing guidance to their species from within the fortified safety of their homes. Rachni queens genetically share memories and knowledge across generations.
* Rachni Workers - the smallest and weakest, but most populous, of the rachni, the multitudes of rachni workers provide for their hive and see that all its needs are met. Although they have few defenses, as a last resort rachni workers are able to induce a suicidal explosion that releases toxic biochemicals from within their bodies.
* Rachni Soldiers - larger and slower than workers, soldiers are able to spit toxic chemicals. They are the main defense of the rachni and there are countless numbers of them in a hive.
* Rachni Brood Warriors - even larger than soldiers, these rachni are uniformly male and provide tough, stringest defenses for the hives. Many brood warriors have biotic capabilities.

Rachni perceive sounds in both an auditory and visual capacity -- sounds appear to them as colors. Rachni were once believed to communicate telepathically, but in fact communicate via pheromones, as well as an organic quantum entanglement communicator.

## History

The rachni originated in the small habitable area of the planet Suen. Due to the inhospitality of the planet's surface, they learned to thrive underground.

At the height of the Prothean Empire, the rachni were discovered. The Protheans took the most cunning and warlike queens, and bred them -- creating rachni they hoped to use as a weapon. The rachni, however, could not controlled. The Protheans fought against the rachni and destroyed as many as 200 rachni occupied planets before believing they had driven the species to extinction. Despite their efforts, rachni remained on Suen and their ranks quickly replenished.

As they developed as a species, the rachni began to construct cities on the surface of Suen, and soon built spaceships. The first planet the rachni visited was Kashhaptu. On that planet, in the crater the rachni named "the howling gulch", the rachni discovered Element Zero. They studied it -- learning of the biotic properties it could bestow upon certain members of their species.

### Rachni Wars

Centuries later, salarian explorers arrived through a mass relay into the Maskim Xul system. The rachni captured these explorers -- and from their spacecraft learned how to utilize Element Zero for faster-than-light travel. The rachni suddenly began to expand their territory more rapidly than ever before.

The Citadel Council attempted to negotiate, but was unable to reach the queens in their hives. Cycles of open war followed -- the Rachni Wars. For many cycles it seemed the rachni would inevitably win due to their overwhelming numbers. Then the krogan entered the fray on behalf of the Citadel. The krogan had the numbers to fight their way through the rachni, and the resilience to get into the hives on rachni-inhabited worlds. By 1100 CE, the rachni were declared extinct. Again.

Listening Post X-19 was left near Suen to monitor for any surviving rachni.

### Reemergence

Centuries later, Binary Helix discovered a rachni ship adrift in space -- inside, eggs were discovered in cryostasis. The company employed scientists to recover one of the eggs and bring it to the Peak 15 facility. The intent was to clone the egg and create an army -- unfortunately, the egg was soon revealed to be that of a queen: Matriarch Benezia.

Once the queen matured, she began to lay eggs. The eggs were removed from her presence by Binary Helix employees, who still hoped to control them. Without the chance to sing to the eggs, however, the rachni within were driven insane. Benezia asked Commander Shepard to help kill her frenzied children. Afterwards, she promised Shepard to find a place to live in peace and not to attack other species if he allowed her to live. Shepard released her.

Cerberus, it soon turned out, also pursued turning the rachni into weapons through cloning. This project led to a disastrous end -- all involved were killed by rachni, who were ultimately wiped out by Shepard.

Benezia stayed true to her word, although she would come into peaceful contact with at least one asari. Through this asari, she passed word along to Shepard that she had come to believe he was fighting an enemy who had long ago "soured the song" of the rachni, and that she was building an army to help in that fight. Shepard believed she was speaking of the Reapers.

During the Reaper Invasion of 2986, Shepard discovered Benezia's hive on Utukku -- unfortunately after the Reapers indoctrinated the majority of it. Though Benezia was still free-willed, many rachni had been converted into Ravagers and Swarmers. Shepard saved her once more, and she sent her workers to aid in the construction of the Crucible.

Despite having joined the greater galactic community cooperatively in this instance, the rachni still preferred isolation. Although they were much more peaceful to other species after these events, they remained hidden on largely uninhabitable worlds. If -- after being warned -- other species persisted in violating the territorial borders of the rachni, the insectoids would attack ruthlessly. Most rachni worlds would be orbited by warning beacons placed there by the Citadel Council or, later, the United Federation of Planets.

## Culture

The rachni are an extremely territorial species, and very isolationist. They typically inhabit worlds that would be utterly inhospitable to most lifeforms.

The rachni are often mistaken for mindless animals but are, in fact, extremely intelligent. They achieved many great technological feats, including spaceflight and cryostasis.

Each hive is led by a queen, but the hive itself is treated as a team and each member of it is carefully nurtured. No soldier is treated as disposable.

Because of their unique perception of sound, all speech is considered singing to them. As such, they refer to their homeworld as "the Singing Planet" and death as "the Great Silence." When they actually are required to speak, their speech patterns are often considered unusual and often consist of almost lyrical metaphors.

## Source

The rachni are derived from *Mass Effect*. For canon information, please visit Mass Effect Wiki.