| Clue | Source | Date |
|---|---|---|
| Carpenters' union? | LA Times Daily | 11 Oct 2025 |
| Underground tunneling group | Universal | 19 Jun 2025 |
| Underground group with many workers | Universal | 29 Sep 2024 |
| Army base, perhaps? | ||
| Certain underground society | ||
| Queen's realm? | New York Times | 12 Jan 2021 |
| Home to millions of workers, perhaps | USA Today | 24 Feb 2020 |
| Insect group with a queen | Universal | 12 Dec 2019 |
| Subterranean labyrinth | Wall Street Journal | 17 Oct 2015 |
| Subterranean labyrinth |