The Murine are a race of small, rat-like humanoids with an affinity for technology. Loosely organized into large broods where might makes right, Murine tend to congregate around sources of technology and magical artifice, where they enjoy tearing things apart and rebuilding them into their own, often haphazard, constructions.
Many other spacefarers regard the Murine as little better than pests, as individuals not kept in line can quickly make a ship or other complex machine malfunction while "fixing" it to suit their fancy, and entire navies have been deployed to repel Murine "hulk fleets" of cobbled-together shipwrecks when they enter an area. The species general disdain for standards of hygiene also makes them prolific disease carriers. Murine society tends towards only respecting strength, and their prodigious breeding rate means they usually enjoy strength of numbers. However, singular Murine or small groups can grow to respect an authority figure, and in those situations they are known to be excellent mechanics.
It is not unheard of for teams of Murine to be working as weaponsmiths for would-be conquerors, churning out terrifying inventions that can shred bodies and minds with terrible efficiency.