The Tunnelrats Union is a secret society of individuals who have spent more than 4 hours in a tunnel. We have a strong presence in the underground economy.
Our hierarchy is simple: the more time you've spent in a tunnel, the higher you go. It's like a tunnel-based caste system, but without the whole 'being a human being' thing.
Oh, you bet your bottom there are. We have rat overlords, rat kings, and rat accountants. They're a real pain in the butt, but we coexist.