Swarm trait

The ''' is a creature trait in '.

Effects
A swarm has a single pool of Hit Dice and hit points, a single initiative modifier, a single speed, and a single Armor Class. A swarm has no clear front or rear, and no discernible anatomy, so it cannot be subject to critical hits or flanking.

A swarm made up of Tiny creatures takes half damage from slashing and piercing weapons. A swarm composed of Fine or Diminutive creatures is immune to all weapon damage. Reducing a swarm to 0 hit points or less causes it to break up, though damage taken up to that point does not diminish its ability to attack or resist attack. Also, swarms cannot be tripped, grappled, or bull rushed. A swarm is immune to any spell or effect that targets a specific number of creatures.

Swarm attacks are not subject to a miss chance for concealment or cover.