For most people, rats are synonymous with pests, unwanted intruders to be chased away or eradicated. But in Tanzania, a very different narrative is unfolding. Here, a unique breed of rat is not just tolerated — it’s celebrated as a life-saving colleague.
In makeshift field clinics and laboratories, these rats are earning their place as invaluable members of the medical community. Their mission? Sniffing out one of the world’s deadliest infectious diseases: tuberculosis (TB).
Meet the African Giant Pouched Rat
Far from the stereotype of a scrappy street rodent scurrying through back alleys, the African giant pouched rat is intelligent, docile, and surprisingly easy to train. In fact, according to those who work with them, they can be even more trainable than certain dog breeds.
These remarkable rodents have proven themselves capable of performing critical medical diagnostics that can make the difference between life and death.
“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,” said Cindy Fast, a behavioral neuroscientist who coaches the rodents for the nonprofit APOPO. “Because our rats are our colleagues, and we really do see them as heroes.”
Life-Saving Scent Detection
APOPO, a nonprofit organization, trains these rats to detect TB by scent in patient saliva samples. This method dramatically increases the detection rates in areas where resources are scarce and conventional methods fall short.
In some Tanzanian clinics, the standard human-performed microscopy test detects TB in only 20–40% of cases. Enter the giant pouched rat — with a sense of smell so keen it could give bloodhounds a run for their money.
One particularly outstanding example is Ms. Carolina, a now-retired TB-detection rat who spent seven years on the frontlines at APOPO. Thanks to her highly developed olfactory abilities, detection rates at her clinic jumped by an astonishing 40%.
Where it might take a team of lab scientists four days to examine the number of samples she could process in just 20 minutes, Carolina’s speed and accuracy made her a vital asset in the fight against tuberculosis.
A Celebration Fit for a Hero
When Carolina retired in November, she wasn’t quietly sent off — she was honored with a heartfelt retirement party. The staff at the clinic baked her a special cake and gathered to celebrate her years of service.
“We’ve made special little rat-friendly carrot cakes with little peanuts and things on it that the rat would enjoy,” Fast said. “Then we all stand around and we clap, and we give three cheers, hip hip hooray for the hero, and celebrate together. It’s really a touching moment.”
By the time she left the field, Carolina had identified signs of TB 3,000 times by detecting six volatile compounds associated with Mycobacterium tuberculosis. Her retirement plans? A move to a shady, peaceful enclosure affectionately called “Rat Florida,” where she now lives with her closest companion and fellow sniffer, Gilbert.
A Disease Not Yet Conquered
While TB is often thought of as a relic of the past — a disease from an era when doctors prescribed “dry air” as a cure — it tragically remains the world’s deadliest infectious disease today. Modern antibiotics have drastically reduced mortality rates in wealthier nations, but in regions like East Africa, it continues to claim lives.
According to Tefera Agizew, a physician and APOPO’s head of tuberculosis, when people witness the incredible capabilities of these rats, they’re quickly won over. “Once people see what the nonprofit’s rodents can do to slow the spread, they ‘fall in love with them,’” Agizew told National Geographic.
Landmine Hunters Too
As if saving lives through disease detection wasn’t impressive enough, APOPO’s giant pouched rats are also frontline heroes in the battle against landmines. Across 67 countries, an estimated 110 million landmines and unexploded ordinances remain buried, posing a deadly risk to countless civilians.
In 2020, there was another report on APOPO’s demining work and one remarkable rat named Magawa. Magawa alone uncovered 39 landmines and 28 pieces of unexploded ordnance, safely clearing an area equivalent to 20 football fields.
Changing Minds, Changing Lives
For those who began this story viewing rats with disgust or fear, perhaps the tales of Carolina and Magawa have inspired a change of heart. These animals, once considered vermin, are now recognized as indispensable, life-saving partners.
Through their work in clinics and minefields, these giant pouched rats are not only altering public health outcomes but also transforming how people view one of nature’s most misunderstood creatures.
In East Africa, they are no longer nuisances — they are heroes.