[quote]If they built themselves, then there must exist a fully organic Vex. If someone else built them... Then they're just sentient milk right? Also, who built them? Why?[/quote] Radiolarian (Vex Milk) is indeed the organic compound made up largely of liquid silica that comprises the intellect of the Vex, which manifests as a hive mind when gathered in quantity. The fluid form is quite literally [b]the Vex[/b], a collection of microorganisms that can be viewed as functioning similarly to self replicating nanotechnology. As it runs over inorganic material, it rebuilds that material into complex structures. And as it runs over [i]organic[/i] material... Well, just look at Asher Mir’s arm. This is likely how the Vex obtained the “mechanical bodies” they have. Some creature came into Radiolarian and was... Processed, shuffled around and made anew. The hive mind liked the results and began processing additional organic compounds it came across to create additional copies. That’s why you take damage when you wade into a pool of Radiolarian fluid on Nessus. It’s literally trying to convert you into something more useful to the Vex, either to create some new form of combat chassis, or just break you down to use as building blocks to create more goblins and minotaurs. (΄◉◞౪◟◉｀)