SIEM REAP, Cambodia, Oct. 22 (APOPO) — Twenty-four newly accredited mine detection rats have arrived safely in Cambodia after leaving APOPO’s training and breeding center in Morogoro, Tanzania, on Monday. The young recruits completed their journey today and will soon join APOPO’s operations in support of the country’s national demining program.
All 24 HeroRATs arrived in good health, and the transfer went smoothly and without delays. Two APOPO Technical Advisors, Mark and Fausta, received the rats at the end of their journey. The smooth arrival reflects APOPO’s careful planning and ongoing commitment to the highest standards of animal care at every stage of deployment.
“All 24 rats have arrived safely in Cambodia,” said Theap Thouen, the APOPO Deputy Program Manager in Cambodia. “The animals are in good condition, and everything went smoothly during transport. Thank you to everyone for the great teamwork and coordination that made this possible.”
From Training in Tanzania to Operations in Cambodia
Of the 24 arrivals, twenty have been earmarked for live mine clearance operations across Cambodia, while four will join the APOPO Visitor Center in Siem Reap to demonstrate the HeroRATs’ unique abilities to visitors and supporters. The rats are the latest to graduate from APOPO’s long-established training program in Tanzania, where each animal spends several months learning how to safely and accurately detect the scent of explosives buried underground.
Before deployment, every rat must pass APOPO’s internal accreditation process—a rigorous evaluation designed to ensure they can perform to the highest standards in real minefield conditions. During training, the rats are taught to associate the smell of TNT and other explosive compounds commonly found in landmines and unexploded ordnance with a click sound followed by a food reward, usually a small piece of banana or peanut paste. Over time, they learn to ignore other background scents and respond only to the target explosive odors.
They then progress through a series of increasingly complex exercises, starting in small training boxes and ending in outdoor plots that simulate real minefields. To earn certification, each rat must pass a blind test in which only independent evaluators know the location of buried targets. The rat must indicate every sample correctly, with zero false alarms or missed mines. Only then are they officially recognized as operational HeroRATs and cleared for deployment abroad.
What It Takes to Become a HeroRAT
APOPO’s HeroRATs are African giant pouched rats—intelligent, social, and extremely capable scent detectors. They are large enough to be easily handled yet light enough not to trigger pressure-activated landmines when walking over them. Their keen sense of smell allows them to locate even minute traces of explosive odor in the ground, making them an invaluable complement to conventional mine-clearance tools such as metal detectors.
Working with a human handler, a trained rat systematically searches a section of land by moving back and forth along a rope grid. When it detects the scent of explosives, it signals by scratching the ground. Each area is then verified and cleared by APOPO’s demining teams using manual excavation tools. A single rat can search an area equivalent to a tennis court in around 20 minutes—a task that could take a human deminer using a metal detector up to four days.
The rats’ efficiency not only speeds up land release but also reduces costs and allows APOPO to focus resources where they are most needed. Once deployed, every rat continues to work under close supervision, with regular refresher training, rest days, and veterinary care to ensure their welfare and reliability.
APOPO in Cambodia
APOPO has been working in partnership with the Cambodian Mine Action Centre (CMAC) since 2015 and Mines Advisory Group (MAG) since 2020. Together, they deploy mine detection rats alongside highly skilled human deminers to accelerate clearance efforts in some of the most contaminated provinces, including Siem Reap, Battambang, and Preah Vihear. Cambodia remains one of the most heavily mined countries in the world, with millions of landmines and items of unexploded ordnance left behind after decades of conflict.
Since operations began, APOPO and CMAC have safely cleared millions of square meters of land, returning it to local communities for farming, housing, and development. Beyond clearing dangerous explosives, APOPO’s work in Cambodia also provides employment, builds local capacity, and supports the government’s goal of making the country mine-free by 2025. The arrival of the new recruits represents an important reinforcement of that mission.
Expanding Capacity and Raising Awareness
The newly arrived HeroRATs will now undergo a short acclimatization period to adjust to Cambodia’s soil, climate, and local handlers before being assigned to operational teams. Their arrival expands APOPO’s capacity to clear more land and return it safely to local communities, helping families rebuild lives free from the fear of hidden explosives.
Four of the new arrivals will remain at the APOPO Visitor Center in Siem Reap, where they will play a different but equally vital role. These demonstration rats help visitors from around the world understand how APOPO trains and deploys its HeroRATs and the life-saving difference their work makes in mine-affected communities.
Through guided tours and live demonstrations, visitors can see the rats in action, meet their handlers, and learn more about Cambodia’s progress toward a mine-free future. The center provides a valuable platform for education, outreach, and inspiration—giving the public a chance to connect directly with APOPO’s mission and the extraordinary animals behind it.
Before starting in their new roles, the rats will first enjoy a week of rest before spending around six weeks adapting to their new surroundings and working with their Cambodian handlers. During this period, they will complete their final accreditation and licensing process with the Cambodian Mine Action Centre (CMAC) and the Cambodia Mine Action and Victim Assistance Authority (CMAA). Once fully certified, the rats will be deployed to operational teams across the country to begin live mine detection work.
A Shared Commitment
Every rat deployed to the field represents years of research, training, and care, supported by a global network of donors, partners, and staff who believe in a safer world free from the threat of landmines. The arrival of these 24 young HeroRATs is not only a milestone for APOPO but also a symbol of continued progress toward that shared goal.
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