A mynock is a leathery-looking silicon-based organism that grows up to 1.6 m (5.25 ft) long, with a wingspan of up to 1.25 m (4.1 ft), and that feeds on electrical energy. They are often found leeching power from spacecraft, as mynocks are one of the few species capable of living in the vacuum of space, feeding on stellar radiation, silicon and other minerals from asteroids and other space debris. Mynocks' bat-like wings also allow them to fly in the atmosphere. Found across the galaxy (having spread prolifically from their original system), mynocks tend to flock together, migrating annually in large groups. The most notable of these events are the migrations of Roon, during which the sky darkens from swarms of these creatures.