Its smell is unnoticeable or unpleasant to breeders until they reach about 35 Pak years (or 42 human years, i.e. early middle age); after that, the smell suddenly becomes irresistible. Even if too old, hominid breeders are still irresistibly attracted to the root's smell. The breeder gorges on the root, infecting himself with a symbiotic virus in the root and triggering the transition; an enzyme works profound changes at the cellular level of the Pak causeing apparent, emotional and intellectual transformations.