[@Polaris North], They're not bulletproof. At least not the rank and file of them. A gun or several guns thoughtfully provided by ECPD, will easily make a human a 1v1 match for a Swarm rat. However, the sheer numbers of the Swarm is why you need Epics and Freaks; Spectrum took out three in a matter of seconds, and she's not even particularly offense-focused as an Epic. More destructive powers could wipe the entire horde out, so feel free to go hog-wild with your powers, guys.

[@Mercenary Lord], only if he's willing to cause mass upheaval (turning buildings on their sides or upside-down would be a serious strain on them). But his 'lair' for lack of a better word is about as alien in geometry as is physically possible.