The Nanobots were originally created by Jimmy to be his bodyguards against a bully. The Orange Nanobot is the self-proclaimed captain while the Red Nanobot is the "stewardess". They first appeared in "Safety First" to protect Jimmy, but started to take nearly every gesture to Jimmy as a physical threat, terrorizing his friends. Jimmy used confusion (aka punching himself) to defeat them.
Jimmy attempts to reprogram them in "Return of the Nanobots" to check for errors in his non-science homework, but still prove to be unstable. Unsatisfied, the Nanobots follow Jimmy to school and start correcting everything they perceive to be an error, such as Ms. Fowl's hair and Cindy and Libby's fashion sense, how ever they seem to like the fashion change that they made. Thinking it would work a second time, Jimmy tells them that humans are meant to have flaws, which causes them to start deleting everyone in the world. Their trash bin soon becomes full, so Jimmy tricks them into overloading by correcting the value of pie (π), thanks to his dad. (he put 3 when it's 3.14...an endless number).
They try to help Jimmy with modifying his dad's toys in Fundemonium, but to no avail. Hugh makes the mistake of using the Nanobots as batteries for his Malibu Death Machine toy, and thinking it was a form of gratitude to Hugh, make it bigger and badder. Jimmy uses the circuitry from one of his dad's previous toys to shut down the Death Machine and beat the Nanobots one final time.
They are not so much villainous as they are misguided. Everything they do is simply to get their creator (Jimmy) to want them back. Even so, Jimmy himself seems to consider them psychos, as he once had them locked up in a manner similar to Hannibal Lector.They're voiced by Tom Kenny who voiced SpongeBob SquarePants, and Daran Norris who voiced Cosmo, and Timmy Turner's dad in "The Fairly Oddparents".
- The concept of the Nanobots appears to be loosely based on the Cybermen from the British science fiction drama, Doctor Who.
- They re once mistaken as talking batteries.
- They get into fights very fast.
- They are not very smart though, they are scatterbrained, but can understand a few words from Jimmy Neutron.
- They seem to be good Tennis Players.