Class 1 = Hideaway or Drone Cluster (easiest)
Class 2 = Burrow or Drone Collection
Class 3 = Refuge or Drone Assembly
Class 4 = Den or Drone Gathering
Class 5 = Yard or Drone Surveillance
Class 6 = Rally Point or Drone Menagerie
Class 7 = Port or Drone Herd
Class 8 = Hub or Drone Squad
Class 9 = Haven or Drone Patrol
Class 10 = Sanctum or Drone Horde (hardest)