Swarm Damage Type?

[GM Jeff]

Is there a damage type on swarm damage? (bludgeoning, piercing, and/or slashing?) I looked and couldn't find the type under natural attacks.

It could be:

A) Other - B/S/P (But as a secondary attack? That doesn't sound right).

B) No type of damage, it simply deals its damage. (But suppose a creature damaged by a swarm has DR 5/Bludgeoning?)

C) Use the damage type dealt by a similar single creature of the swarm. Example, bat swarm uses dire bat's bite (B/S/P), crab swarm uses giant crab's claw (B/S), etc.

I would go with "C", but is there some rule I'm missing on this?

[Starglim]

It's a special ability that deals non-magical, non-energy, untyped physical damage. DR applies but it's neither a weapon nor a natural attack.