Nanovore
From Tardis Wiki, the free Doctor Who reference
Nanovores are microscopic robots, probably similar to to Nanoforms (SJA: Prisoner of the Judoon) and Nanogenes. (DW: The Empty Child/The Doctor Dances) At some point they attack the Doctor and Donna Noble on floor 139 of the Edifice. (NSA: The Forever Trap) They are, apparently, capable of "eating" absolutely anything.