APOPO is a Belgium-based humanitarian organisation, famous for training Tanzanian rats to save lives across the world. On 28^th April NIVA members gathered (virtually) to hear Anna Bouchier, Swiss and European Development Director of the charity, describe its history and current work.

The charity has been training rats to clear minefields in post-conflict regions since 1997. It was the brainchild of Belgian founders Bart Weetjens and Christophe Cox, the former of whom bred pet rats as a hobby and observed minefield problems first-hand while travelling as a student in Angola and Mozambique.

APOPO’s training centre is situated in Morogoro, Tanzania and uses Southern African giant pouched rats (Cricetomys ansorgei). These adaptable, intelligent, social, and mainly nocturnal omnivores typically weigh in at between 1and 1.5kg – 2 or 3 times the size of our local European varieties. They are known for their amazing sense of smell (compensating for poor eyesight) because they use olfactory cues to communicate long distance in the wild, and have been selected for heroRAT training because they are also ubiquitous, resistant to local disease, easy to transport, easy to  transfer between trainers, and long enough lived to repay the training investment.

Anna was at pains to point out that animal welfare is at the very heart of all that APOPO do. All the rats are the product of a dedicated breeding programme and extremely well cared for throughout their lives. Training starts with socialisation and habituation from 4 weeks of age and progresses to reward-based operant conditioning, which takes between 9 months and a year in total. Down-time is spent in rich and stimulating play cages or resting in cosy clay-pot nests. Vet checks are regular and natural diet and behaviour are respected, with working hours being early mornings or evenings, and weekdays only. The rats typically live for 6-8 years and only work for as long as they want to. At the first sign of any waning of enthusiasm for the task, they are retired to luxury accommodation at the training centre.

No animal has ever been harmed on active duty. It would be unlikely that a rat would trigger a landmine as they typically require 4-5kg pressure to cause deployment, but it is more impressive that the rats have never missed a mine that has subsequently exploded. Accreditation requires the rats to clear 400 sq m of mines without missing any targets and with no more than one false ground scratching indication. Amazingly, in contrast with humans in a “rat race”, they demonstrate little propensity to cheat to gain reward!

The rats can clear an area the size of a tennis court in 30 minutes, compared to 4 days for a man with a metal detector. They are particularly efficient in short scrub or desert, however the length of their legs proved to be a limitation in dense bush and the jungles of Cambodia, leading to APOPO opening a facility training Technical Survey dogs. These Belgian Shepherds carry GPS backpacks with a microphone and camera, enter dense scrub unaccompanied, and sit to indicate 1 metre from any unexploded ordinance. The dogs may miss targets, but this technique allows large areas to be assessed for contamination before sending rats in to micro-search.  

In 20 years APOPO’s heroRATs and heroDOGs have cleared over 108,700 landmines and released millions of square metres of land for safe farming. This work will be ongoing for some time – despite the Ottawa convention, 60 countries have remaining minefields and there were almost 6000 mine-related accidents in 2019,  43% of which involved children.

Ten years in, APOPO’s work diversified into training rats to detect another deadly global threat – TB, in sputum samples. Prior to Covid, TB was the world’s most deadly infectious disease with 1.3 million deaths in 2019 alone. It spreads easily in densely populated areas and, as the leading killer of HIV patients, Is particularly deadly in Africa. In Europe, the gold-standard for diagnosis is culture, which takes a week to produce a result, during which time the patient must isolate. Molecular testing needs expensive hardware, electricity and internet connectivity, so the current African solution is microscopy…which is fairly quick, but only 50% accurate. This is where the rats come in. In 20 minutes a trained rat can assess 100 (heat-treated and therefore safe) samples, and, to date, the program has picked up 20,000 positive TB cases which had slipped through the microscopy net, allowing timely treatment and prevention of further spread to contacts. Fascinatingly, for reasons unclear,  the rats are particularly quick and accurate at detecting cases in children.

Future uses for the skills and talents of these fabulous animals seem practically limitless. The scope for detecting other pathogens and diseases is obvious and exciting, as are the prospects for detecting trafficked wildlife, drugs and other contraband, and environmental contaminants. Work is even under way in training “rescueRATs” with tiny smart backpacks to search rubble for survivors.

NIVA would like to thank Elanco for their generous sponsorship of Anna’s talk, and helping to raise awareness of the amazing work of this excellent charity and a much-maligned species. Anyone reading this who isn’t so keen on our long-tailed friends could do worse than visit the APOPO website (https://www.apopo.org/en) – I cannot imagine how even the most determined musophobe would not be beguiled by pictures of these beautiful and intelligent creatures in action, saving human lives.