In 31 BBY, Nia and San were engaged in rather one-sided trading with the Hiironi irstat. They would take high-end technological goods to the Tarasin in exchange for native crafts of much lesser value. They hired laborers in Gadrin to help them transport the goods. Most of things that Nia and San took the Hiironi were things that the Tarasin did not need, but the Tarasin saw that it made Nia and San feel good to help out the "primitives," so they let it continue.
Nia and San were killed in 19 BBY, when Len Markus touched them with the Darkstaff and turned them into zombies.
- Droids, Technology and the Force: A Clash of Phenomena on Hyperspace
- The Complete Star Wars Encyclopedia