
scary harpy |

Vermin Empathy (Ex) This ability functions as a druid's wild empathy, save that a mite can only use this ability on vermin. A mite gains a +4 racial bonus on this check. Vermin are normally mindless, but this empathic communication imparts on them a modicum of implanted intelligence, allowing mites to train Medium vermin and use them as mounts. Vermin empathy treats swarms as if they were one creature possessing a single mind—a mite can thus use this ability to influence and direct the actions of swarms with relative ease.
How much should this trait cost? Would this be a Magical or Other trait?
Thanks.

Fuzzy-Wuzzy |

I wouldn't put it under Magic since it's not a spell or spell-like ability. Other is probably right.
a mite can thus use this ability to influence and direct the actions of swarms with relative ease.
Can a mite use this to just control any vermin swarm they happen across? That's really, really powerful.
Swarms aside, I'd call normal wild empathy 2-3 RP (i.e. about a feat's worth). Basic vermin empathy should be equivalent, but this has the implanted intelligence thing going for it too, so call it 3. Again, that's ignoring the power over vermin swarms 'cause I'm not sure how strong it is.