The Skorpius Flies were a type of colonial insect. Each Skorpius fly was small, blue and luminescent. These flies would group together in a swarm, forming a brain-like structure with long tendrils at the bottom. Though they developed a hive mind this way, they had little intelligence and were more concerned with food than other matters.
A group of Skorpius flies was captured by the American government and was brought to the Area 51 vault. Despite this, they managed to escape, forcing the vault to be closed down. In 1958, the Tenth Doctor and Seruba Velak came to the vault to find remains from the Roswell crash. Though they were chased by a swarm of Skorpius flies, they were able to escape by hiding in a crate. (TV: Dreamland)