Nanochip

Nanochips (aka Microchips or Nanites) are objects used in Ben 10: Alien Swarm by the hive. The Queen produces them from her body and later after she takes up residence in Victor Validus body, she produces them from there and they have the ability to take over a person's mind. They are a hybrid which is part organic matter and part machine as pointed out by Kevin. The Queen was destroyed by Ben in the form of Nanomech.

The nanochips surprisingly returned in the Ben 10: Ultimate Alien episode Revenge of the Swarm. The team discovered that the chips took over Elena Validus' mind and had made her the Queen of the Hive. After Elena sacrificed herself for Ben by destroying her nano self, the chips still had some life in them.