Carolina the giant rat retires as a hero after saving many lives

“Everybody’s first impression is that the rats are our enemies,” Tefera Agizew, a physician and APOPO’s head of tuberculosis, says of the animals’ reputation in Africa and beyond. “Once they see how they function, they fall in love with them.”

African giant pouched rats are not your typical New York City–style rodent. They’re calm, easier to train than some dogs, and able to work up to seven or eight years (they live eight to 10 years in captivity). Their body alone is generally longer than a 13-inch MacBook Air—and their tail is equally as long, if not longer. (A New York City rat is only about 16 inches, nose to tail.) A giant pouched rat’s sense of smell is so strong that they could conceivably detect half a drop of chlorine in a space the size of 20 Olympic-sized swimming pools, says APOPO’s head of training Cindy Fast, a behavioral neuroscientist who coaches the rodents.

And while rats may be much-maligned in society, Carolina and her peers in East Africa have raised detection rates for TB—the leading cause of death worldwide by infectious disease—by 40 percent at local clinics, where patient samples undergo a smear test under a microscope that is, according to Agizew, usually only 20 to 40 percent accurate. (A more accurate rapid test is less available and more expensive.)

And for every tuberculosis infection detected by a rat, it’s estimated that 10 to 15 more humans are saved from an infection, since each tuberculosis patient tends to spread it to that many new people.

All told, the program prevented nearly 400,000 new cases last year in Tanzania and Ethiopia alone, Agizew says. “Not only are we saving people’s lives, but we’re also changing these perspectives and raising awareness and appreciation for something as lowly as a rat,” Fast adds. “Because our rats are our colleagues, and we really do see them as heroes.”