The Singing Rodent Hives of Xargon

On the planet Xargon, there exist a race of singing rodents. They live underground in a hive-like network of tunnels beneath Xargon's crytaline crust. Though these mole-like creatures are tiny and seemingly defenseless, they are the dominant species of Xargon because of their unique ultra-sonic singing ability. Their song gives them a kind of "collective hive mind," allowing them to respond to predators or natural disasters as a single, intelligent entity. Also, scientists have observed them using the song as a kind of "mental weapon" against would-be predators.