the wandering worm primarily takes up residence in rats’ lungs, where female worms lay their eggs. Young worms leave the nest early to find their own windy home

the wandering worm primarily takes up residence in rats’ lungs, where female worms lay their eggs. Young worms leave the nest early to find their own windy homes, though. Larvae get coughed up into rats’ throats then swallowed. The hosting rat eventually poops out the young parasites, which then get gobbled up by feces-feasting snails and slugs (intermediate hosts). When other rodents come along and eat those infected mollusks, the prepubescent parasites migrate to the rats’ brains to mature before settling into the lungs and reproducing. The cycle then starts again 1. rat lung 2. rat throat 3. rat stomach 4. rat poop 5. slugs 6. rat brains 7. rat lung 8. GOTO 1 It never ceases to amaze me, the life cycle of a parasite. So that's 7 steps with wildly varying probabilities of success. That it actually works is mind blowing.