Board Thread:Speculation House/@comment-27966940-20170315165354/@comment-27144409-20170318015329

Nanobots, depending on their design, can assemble, assimilate, construct, consume, repair, replicate, combine into new designs, refine materials, and/or even heal organic issue.

I might be forgetting more things they can do in fiction.

One doomsday scenario, the so called "grey goo," is just the unchecked replication of Nanobots and the consumption and processing of matter to create more units.