| Clue | Source | Date |
|---|---|---|
| They build a nest on moss somehow (11) | ||
| Rock workers | ||
| They build a nest on moss, maybe! (5-6) | ||
| They build a nest on moss perhaps | ||
| Craftsmen's mothers working in pits | ||
| Blockheads? | New York Times | 08 May 2015 |
| Blockheads? | ||
| Quarry men | ||
| Certain builders |