Ages ago, terrified by a barrage of meteor impacts, they feared that their planet would go through an ice age and they retreated underground in suspended animation. They constructed a sonambutron which would re-activate them again in the next solar eclipse, however they would not predict that in the meantime the planet's moon would be destroyed. Those Nauians that remained on the surface degenerated into a cat sized insects called Silotis and were the largest native life form on that world.