Swarms with an attack bonus?

[LordPretzels]

what is up with some swarms having an attack bonus? does that mean they have to roll an attack upon entering a square instead of doing their automatic swarm damage?

examples
Parasite, Rot Grub Swarm (bestiary 3), Ubashki Swarm (campaign setting, lost kingdoms)

[Nefreet]

I don't see any attack bonus for the Rot Grub Swarm.

[Nefreet]

As for the Ubashki Swarm, monster statblocks from APs and Player Companions are known to contain numerous errors. They're generally not regarded as being good sources for rules interpretations. They just don't receive the same editing scrutiny as the hardbacks.

In this case it appears the +7 comes from Dex (+3), BAB (+2), and Tiny (+2), so at least the calculation was correct.

[LordPretzels]

bestiary 3 has rotgrub swarm as a "+10 (2d6 plus swarmness" but it looks like it was edited, thanks for linking to the reference doc.

i was curious if it was just a mistake or if it was some exception.

[Nefreet]

Just a mistake.

[Brf]

Errata wrote:

Page 215—In the Rot Grub Swarm stat block, in the

Melee entry, delete “+10”.