Gulp: Adventures on the Alimentary Canal

Roach investigates an urban legend circulating among reptile and amphibian enthusiasts: the claim that mealworms and superworms can survive being swallowed and subsequently chew their way out of their predator’s stomach. This phenomenon allegedly occurs within seconds of consumption, leading some pet owners to crush the insects’ heads before feeding them to their animals.

The author traces conflicting perspectives on this claim. Mealworm suppliers dismiss the stories as folklore, arguing that insects incapable of quickly consuming soft vegetables could never escape stomach tissue. Conversely, some reptile dealers and online forum users insist they have witnessed or heard firsthand accounts of this occurrence. Roach notes the difficulty of finding actual eyewitnesses, though she interviewed one person who claims to have observed this as a child.

To resolve the debate scientifically, Roach collaborated with University of Nevada researcher Richard Tracy, who designed controlled experiments using borrowed medical equipment. Tracy’s team used an endoscope to observe live superworms inside sedated frogs and lizards. Their findings revealed that while the insects remained alive inside stomach environments, they became completely motionless due to what researchers term the “blanket effect”—a calming response to being compressed by stomach walls.

Additional experiments demonstrated that mealworms show remarkable resistance to hydrochloric acid, the primary digestive acid.