Grey Goo

Grey goo, or gray goo, is a term which refers to a hypothetical end-of-the-world event involving molecular nanotechnology where out of control self-replicating robots devoure all living things on Earth while cloning themselves (a scenario known as ecophagy).
In a worst case scenario, everything in the universe could be turned into goo (with "goo" meaning a large mass of replicating nanomachines lacking large-scale structure, which may or may not actually appear goo-like), killing the universe's creatures. The disaster is posited to result from an accidental mutation in a self-replicating nanomachine used for other purposes, or possibly from a deliberate doomsday device

When these self-replicating robots arrive on Earth we should in fect them with diseases that we have already become immune to or diseases that we have a cure for. This will kill off all of the robots and stop them from devouring our planet and turning it into goo.

self-replicating is the procces in which things make copies of themselves, and Cloning is the process in which humans make copies of other creatures. Self Replication is more of a threat to us 12 on the planet Garulak becauase if several enemies come to our planet, we might be able to defeat them; but if they can replicate themselves to produces hundreds, or even thousands of themselves..... there would be a sreious problem on planet Gargulak.

websites about grey goo
1.) http://www.iop.org/EJ/news/-topic%3D763/journal/0957-4484
2.) http://www.crnano.org/BD-Goo.htm
3.) http://www.gyre.org/news/related/Nanotechnology/Grey+Goo