Small and Vermin Familiars
System: Pathfinder | SRD | Type: familiar
Small-sized familiars threaten the areas around them like Small creatures, and can be used to flank enemies, though both familiars and their masters are often loath to use such tactics, as the result is often a dead familiar. Small-sized familiars are also harder to keep on a master’s person than Tiny or smaller familiars. Often they require some form of magic item, like a bag of holding, for such a feat to work.
The process of making a vermin into a familiar grants it an Intelligence score and removes the mindless trait. Vermin familiars communicate with their masters and other vermin of their kind (greensting scorpions with other scorpions, house centipedes with other centipedes, and scarlet spiders with other spiders) by way of a strange combination of behaviors, slight changes in coloration, and even the excretion of scents, subtle and otherwise. As with other types of familiars, other creatures cannot understand this communication without magical aid.
Source: d20pfsrd