Xenomorphs. Villains and enemies help make for good stories but sometimes you need to have your heroes go up against an unrelenting force they cannot defeat by regular means. While inorganic species may not be able to be infected by the Xenomorphs, their robotic bodies can still be damaged by the Xenomorphs tail, claws and bodily acids. If you run into a Xenomorph nest while adventuring in Microspace it is best to run away and nuke the site from orbit (it's the only way to be sure ... lol).