n large animal swarm 

Perception +5; low-light vision, scent (imprecise) 30 feet

Skills Acrobatics +8, Athletics +4 (+6 to Climb or Swim), Stealth +6

Str -2 Dex +3 Con +1 Int -4 Wis +1 Cha -3

AC  14; Fort +2, Ref +7, Will +4

HP 14; Immunities precision, swarm mind

Speed 30 feet, climb 10 feet

Swarming Bites [>] Each enemy in the swarm's space takes 1d6 piercing damage and must attempt a DC 17 basic Reflex save. A creature that fails its save is exposed to filth fever.

Filth Fever (disease) The sickened and unconscious conditions from filth fever don't improve on their own until the disease is cured. Saving Throw DC 14 Fortitude; Stage 1 carrier with no ill effect (1d4 hours); Stage 2 sickened 1 (1 day); Stage 3 sickened 1 and slowed 1 (1 day); Stage 4 unconscious (1 day); Stage 5 dead

Bestiary, page 276.