Related Clues:
- When order is reversed to produce a low hum
- One that owes one is no worker
- Male honey bee - hum
- He buzzes, but not with energy!
- Male bee - monotonous hum
- Monotonous sound - member of hive
- Sustained bass note accompanying a melody - male bee
- Queen's attendant doctor and I
- Unmanned flier
- Male wasp
- Predator ___
- Stingless male bee
- High-tech surveillance tool
- Plane without a pilot
- Spying aircraft