Sontaran drone
From Tardis Wiki, the free Doctor Who reference
The Sontaran drone was a type of technology used by the Sontaran Empire.
Sontaran soldiers often made use of these drones which appeared as balls of light that were capable of hovering across their environment. They fed information of what they discovered back to the soldier that deployed them.
A number of drones were let loose by Commander Kaagh when he crashed on Earth which he used to distract Humans while he attempted to use a radio telescope to bring about the destruction of the world. These drones were later deployed against the "half form" children that were friends to Sarah Jane Smith. They were destroyed by Sarah Jane through the use of her Sonic lipstick. (SJA: The Last Sontaran)
