In my latest draft, a worm-like species buries itself deep below the crust of their world and consumes/gathers tiny amounts of heavy metals.
Can you think of any plausible reason why a wormlike creature would do so? Why would they spend time and energy digging deep and gathering small pieces of metal?
- Location: Earth-analog
- The species itself is not really fleshed out right now.
- They do return to the surface. Its either part of their lifecycle or daily/weekly/monthly routine.
- the intake of metal takes places many hundreds of metres below the surface, at least 1000 metres below. I should make the heat-resistant, or should I?
- the metals take a significant amount of their worms bodyweight.
Bonus Question: Is that deep below the surface a suitable place for heavy metals or do I need to mess with the geology of my earth analog for this?
Edit: As Suggested by John Dallman the plot reason for this:
The worms are harvested by humans, who need the heavy metals. It kind of harvesting spider silk in terms of quantity, maybe a order of magnitude higher in output. This work should be dirty, dangerous and really unpleasent for the poor peasants.