Bugs

Bugs are the working animals of vermin civilization. They range in intelligence from "unable to comprehend their own instincts" to "tamable, trainable, and capable." Vermin use bugs for livestock, transportation, guardians, pets, and much more.
A crew is able to gain access to domesticated bugs in three ways. The first is to use the Acquire Asset downtime task to gain a bug for temporary use. Second, they may spend two crew upgrades to gain a bug permanently. Bugs gained in this fashion are as loyal to the crew as any other cohort, to the limit of their faculties. Even a dung beetle knows who's feeding her.
Thirdly, the crew can capture a bug from the wild or another vermin faction. Bugs obtained by force, subterfuge, or treachery will often require a long-term project before they are usable by the crew. This could represent taming a wild bug, retraining a captured bug to respond to your commands, or gaining the trust of a liberated bug that was abused by harsh masters.
Whatever manner the crew comes by a loyal bug, it functions as an expert cohort. A bug always has the "directed" flaw: a bug will do whatever it is told to do, and little else. They simply aren't capable of the higher thought necessary to be an independent agent. As for their expert type, it is simply their species. A scorpion, for example, is very good at grappling, stinging, and hunting, and little else.

Several Legacies start with a choice of bug as a special gear option. You don't need to choose which bug you have until it becomes relevant in the fiction, but once you do, that's the only bug you get for free. Keep it healthy.
Gnawbones Bugs:
Leech: good at swimming, hiding, drinking lots of blood.
Mosquito: good at dodging, distracting, drinking a little blood.
Quartermouster Bugs:
Millipede: good at moving steadily, carrying cargo, curling defensively.
Scarab: good at discerning value, laden flying, burrowing.
Shipsqueak Bugs:
Cricket: good at quick getaways, being loud, sensing danger.
Flea: good at filching, jumping, being annoying.
Swashnibbler Bugs:
Firefly: good at signaling, pattern recognition, flying stealthily.
Powder Weevil: good at loading guns, smelling powder, starting fires.