I have an alien species similar to a caterpillar, the original idea was that the creature could eat different materials, digest them then combined with a very sticky liquid created in its body, it could spit it out in strings to form different structures.
Other than eating wood I originally wanted it to be able to eat metal ores to create really strong structures and pieces, eventually with a precision almost like a 3d printer.
This creature will also have the ability to generate electricity from a symbiotic relationship with electric bacteria or I may choose another method but that isn't too important for this question.
With the creatures ability to produce electricity and spit wires of material I then thought of carbon nanotubes, similar to spider silk covered in carbon nanotubes to conduct electricity.
I have trouble with either option 1) strong enough mandibles to break down rocks with iron, maybe with the help of acid to dissolve it then suck it up as it would have to have strong stomach acid or acid that doesn't replenish itself too regularly to dissolve the metal, and could this metal combined with the spit even conduct electricity 2) the creature naturally creates carbon nanotubes, I don't think this is possible in a living creature but it could be a good solution to add to the creatures sticky strings to both build strong structures and conductive wires.
So my question is what is the most possible situation, a creature that can eat and digest metal from rocks or a creature somehow naturally creating carbon nanotubes?