Here, two Tier 3 Swarm individuals would inject into the live victim a substance, the composure of which is still unknown. Organic hosts would be incapacitated by a toxin produced by tier 1 Swarm (Clackers), then brought to a birthing chamber. Reproduction was accomplished only by Tier 3 types, as this was the only tier to possess reproductive organs. Rather than reproducing asexually, which prevents ongoing genetic variation, The Swarm rely on organic hosts in order to reproduce. The Swarm was not composed of organisms of one gender, rather each individual was hermaphroditic, sharing internal characteristics similar to what would traditionally be called male and female. They all maintained a core body temperature of 26☌, and shared their internal structure with little changes other than size. However, they all shared the same exoskeleton, formed of naturally occurring carbon nanofibre. The Swarm differed greatly between types, in size and many other areas. It was theorised that these variations were not natural in origin but influenced and enacted by some unknown higher being/beings, though this remained totally unfounded. This was supported by the fact that each of the Swarm types shared integral characteristics such as a tough exoskeleton and major internal systems, and shared large quantities of DNA with only a few major variations. After this event they vanished off the galactic radar for more than a hundred years, before reappearing in 2733, triggering the galaxy's most massive, bloody and costly war since the Forerunner-Flood conflict.Īlthough it was first thought that the Swarm was a collective of multiple species, later evidence showed that the Swarm was of a shared genus with several subspecies or variations from what was otherwise a shared genetic code. Due to the infrequent nature of communications between the outpost and the rest of the Allegiance, its destruction was not known until 9 months later. The first confirmed contact with The Swarm was in 2557, when they invaded and massacred the small UNSC scientific research outpost of Radiance. The only evidence for it was carvings in ancient temples and archaic writings in obscure, long-dead languages. It is not known if this event was related to the Ancient War, an apocalyptic event before the de facto founding of The Allegiance. According to the source, it defended the world, along with the Therans, who were technically descended from Forerunners, with 'fire and vengeance'. Based on unsubstantiated evidence provided by an unidentified source on Thera, which may or may not be a Forerunner AI, the Swarm invaded the world of Thera. The Swarm are speculated to have invaded the galaxy once before, long after the time of the Forerunners.