The Sontarans had at least two models of drones. One type appeared as balls of light roughly the size of a football. These could hover across their environment. They fed information of what they discovered to the soldier who deployed them. (TV: The Last Sontaran) The other type of Drone was larger and shaped like a Sontaran Scout Ship, with two arms to manipulate the environment. They had a similar function and were linked by a network to share information. (COMIC: The Betrothal of Sontar)