I wouldn't say extending the lifespan from months to years is "immortal" but reading them repeating the same bullet point over and over felt like an eternity! You can get the point in two paragraphs: >>To complete their complex lifecycles, Anomotaenia brevis tapeworms need to be ingested by birds, and they can survive for years in the ants’ hemolymph until that happens. If or when a woodpecker discovers the colony, the uninfected ants will scramble to grab their larvae and run away, while the lazy “immortals” won’t even bother to escape. >>So it turns out that the tapeworm larvae are just grooming their hosts for their ultimate purpose – to get eaten by birds, so the parasite can complete its life-cycle. It will reproduce inside its main aviary host, and spawn new larvae that spread through bird droppings and infect new ants.