Bug City Express
Fluorescing Astral Bacteria is a dual-natured, genetically modified bacteria designed for astral security purposes. FAB-I is suspended in a special liquid solution, usually kept inside security walls with light sensors; when an astral form such as a spirit or astrally projecting magician passes through, the disturbed bacteria emit light, and this triggers an alarm.
FAB-II was designed to be more portable. It can be sprayed as an aerosol, its glow outlining astral shapes, but its function is essentially the same: to detect astral threats and alert mundane security.
FAB-III, however, is aggressive. It seeks out astral forms, including astrally projecting or perceiving magicians, active foci, dual-natured beings, spirits, and even sustained spells, and it eats them. It sucks the magic right out. Then, when there’s nothing else left, it starts eating the background mana. This has caused most of Chicago to become a massive mana ebb, an area of significantly reduced magic.