In a scene mirroring a disaster zone, a man lies motionless amidst simulated earthquake rubble, awaiting an unlikely saviour: a rat, equipped with a miniature backpack.
With whiskers twitching, the African giant pouched rat navigates the debris of toppled furniture and scattered clothes in Morogoro, Tanzania. Its task is to locate the ‘survivor’ and activate a trigger on its pack, alerting search teams above.
A resounding click signals success; the search is over. The rat, part of an innovative training programme for search and rescue operations, then scurries from the abandoned building, rewarded with a banana for its completed mission.
“Their sense of smell is incredible,” said Fabrizio Dell’Anna, an animal behaviorist at APOPO, a Tanzania-based nongovernmental organization that trains the rats for lifesaving applications. “These rats are able to detect explosives, tuberculosis — even tiny amounts of the bacteria — and in this project, they are able to correctly identify and indicate humans.”
In a field nearby, more rats walk on leashes held between handlers, pacing a grid filled with land mines as part of an initiative by APOPO, which works alongside Sokoine University of Agriculture. When they pause, it indicates that explosives are beneath. These rats are readying for their next deployment, perhaps Angola or Cambodia, where APOPO has helped clear more than 50,000 land mines since 2014.
From detecting land mines to sniffing out tuberculosis, these “hero rats” have become unlikely, and sometimes unrecognized, front-line responders in Tanzania and beyond.
For decades APOPO has trained these “hero rats,” which have one of the most sensitive noses in the animal kingdom. Since 2003, the rats have been finding land mines and, more recently, have been turned on to trafficked wildlife and earthquake survivors.
The rats begin training shortly after birth for specific missions and, with a longer-than-average rodent life span of almost a decade, can spend years carrying out their work. The cost of training each rat runs around 6,000 euros ($6,990).
It is all done with classical conditioning and positive reinforcement, explained Dell’Anna, who oversees the search and rescue program. The first cohort of this group of specialized rats are already in Turkey with a partner search and rescue organization.
While the rats focused on explosives or survivors buried in rubble get all the glory, it is a group of rats inside a lab that are arguably the most impactful lifesavers. These are not typical lab rats, but rather, as their proponents would argue, one of the world’s most effective detectors of tuberculosis.
“Every day as many people die from TB as from land mines in a whole year,” said Christophe Cox, the CEO of APOPO. “It’s more spectacular to be on the minefield … but for TB … in terms of social impact, it’s tremendous.”
Tuberculosis is an ancient respiratory disease that continues to run rampant despite centuries of research and treatment. The World Health Organization said last October in its most recent TB report that the disease had resurged as the top infectious disease killer, with 1.25 million deaths and a record 8.2 million infections in 2023.
In sub-Saharan Africa, only about half of TB patients receive a diagnosis, according to a study by researchers in the UK and Gambia published in the National Library of Medicine, and this leaves them liable to spread the disease. Tanzania struggles with one of the highest global TB burdens, according to the WHO.
APOPO expanded into TB detection in 2007 and its rats have been deployed in Tanzania, Ethiopia and Mozambique. The group works with 80 hospitals in Tanzania, collecting samples daily and bringing them to the lab rats.
