Hidden in it's cave system was a Vidiian Sodality base, where organ transplants were performed and Sulan conducted his research on the Phage. Tunnel digging, using captured aliens, also went on. The area cloaked by the Vidiian technology was more then six hundred kilometers in circumference.
Rodents were present inside the caves and tunnels, as well as something with a distinct cry.
In 2371, an away team from the USS Voyager, consisting of Lieutenants B'Elanna Torres, Tom Paris, and Peter Durst, were investigating magnesite deposits on Avery III when they were captured by the Vidiians. Durst was killed and his organs harvested before the team could be rescued. (VOY: "Faces")