From Guild Wars 2 Wiki
Loose Rocks can be found piled around the southern segment of Draconis Mons.
- Tyler Bearce initially designed the suspicious bushes without [F] interact, instead the player had to throw a rock into them. The logic was that it'd be a lot safer to check out a potentially dangerous bush by throwing a rock into it, rather than "sticking the face into it". However, the early playtesters were confused by this mechanic, so Tyler re-enabled the interact, and decided to leave the 'loose rocks' in as a minor easter egg.