DiSSiPER submitted this

Did you ever get the "Your minions are vandalizing your dungeon!" message,
and, checking your lair, you see nothing wrong? I think I just found out
what's going on. Demon Spawns need to do something. I built a guard post,
and placed all my Demon Spawns in it, and there was vandalism no more. Even
if they were guarding a dead-end, my Spawns were quite happy and content
with their role, and lived in peace and joy thereafter.

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