Formians are rightly feared for their dedication to spread to all planes and all worlds. Not so the colony of formians on Arcadia, or so the myrmarchs and queen are quick to demonstrate to the paranoid einheriar. Their hive-city is called Mandible.

Unlike a common hive-city, Mandible is open and mostly above ground. From the outside, the hive looks like an appealing geometric mix of two- and three-story buildings, parks, and spires. The tunnels hidden below the city are rarely seen by nonformians. Still, visitors are welcome above in the markets and inns.

The Queen Mother K'l'tk'thra (called Clarity by non- formians) rules Mandible from her royal chamber deep within the tunnels. Clarity spends her days overseeing the business of the hive, breeding, and protecting the Place of Eggs.