Once they've gorged on grey matter the brain worms known as Taenia solium kennediae bore their way out of the body to begin their cocooning phase. This has to happen through the skull, so the worms have an ingenious solution to a hard problem; they emit a subsonic hum that drives nearby susceptible persons to fire any firearm in their possession at the hosts head, creating openings for the grown worms. These unwilling midwives are commonly known as Paratsies. While this is a risky strategy, it also has the advantage of concealing the parasites from detection.