Active landmines pose a serious threat in several countries across the world. A report suggests that about 110 million landmines remain buried globally even today. A majority of them are found in African and Asian countries, where limited resources make the detection and removal of these mines especially challenging.

For instance, Cambodia, an Asian country with a population of about 17 million, has about four to six million landmines. In the last 40 years, these mines have killed 20,000 people and injured over 40,000 others. 

Landmine detection and disarmament using existing technology is expensive, both in terms of money and time. For example, while planting a single mine may cost as little as $30, getting rid of it could cost up to $1,000.

A nonprofit named Apopo looked at this problem and came up with what’s possibly the most innovative, practical, and cost-effective approach to deal with land mines. Under their initiative, HeroRATs, they train rats to sniff out mines in various Asian and African countries. Recently, Ronin, one of their hero rats, broke the Guinness World Record for the most landmines detected by a rat.

“Ronin has detected an impressive 109 landmines and 15 items of unexploded ordnance (UXO), surpassing the previous record held by the legendary HeroRAT Magawa, who identified 71 landmines and 38 UXOs during his five-year service,” the Apopo team notes.

“Ronin’s achievements are a testament to the incredible potential of positive reinforcement training. He’s not just an asset; he’s a valued partner and colleague,” Phanny, Ronin’s handler, added.

How rats are trained to detect mines

You might be wondering what the connection is between rats and land mines. Well, rats have a highly developed olfactory system. The part of their brain dedicated to smell is proportionally much larger than in humans. This allows them to detect trace amounts of volatile chemicals, such as TNT (trinitrotoluene), which is commonly used in landmines.

Over time, buried landmines leak vapors of explosive chemicals like TNT into the surrounding soil and air. Even in tiny concentrations, rats can detect these vapors.

Apopo’s HeroRATs program aims to harness this incredible olfactory sense of rats. It involves training African giant pouched rats (Cricetomys gambianus). Training begins when the rats are about 5 to 6 weeks old. At this stage, they undergo socialization to become accustomed to human handlers and various environmental stimuli. Each rat has one human handler.

Next, the rats are introduced to clicker training, a form of operant conditioning (reward-based learning. They learn to associate the sound of a click with a food reward, such as a banana or peanuts. Once the rats have mastered the clicker association, they begin scent detection training. 

They are exposed to the scent of TNT (trinitrotoluene), the explosive commonly found in landmines. During this phase, the rats learn to pause or scratch at the ground when they detect the scent, signaling the presence of explosives. Each correct identification is immediately rewarded with a click and a treat, reinforcing the behavior.

Then the training progresses to more complex scenarios, gradually introducing the rats to environments that mimic real minefields. They practice detecting buried explosives in controlled settings, with the complexity of the tasks increasing over time. 

In the final stage before deployment, each rat must pass a blind test, accurately identifying explosives in a test area without prior cues. Only rats that meet stringent accuracy standards are certified for fieldwork. Certified HeroRATs are then deployed to mine-affected regions along with a human handler. All the HeroRATs, including Ronin, go through this grueling training process.

Saving human lives while caring for the rats

A HeroRAT is expected to live for six to eight years, and they are in the mine detection job for four to five years. During their service years, they only work for 30 minutes a day in the morning; the rest of their time is spent eating, resting, and playing. 

After five years, when a rat is too old to do the job at the highest standard, it is sent to Apopo’s colony of retired rats, where they receive the same care and comfort as a working rat. 

“Our HeroRATs are not just workers; they are cherished members of our team. Ensuring their well-being, both during and after their working lives, is our absolute priority,” Pendo Msegu, an Animal Welfare Officer at Apopo, said. 

Moreover, Apopo also claims, “the majority of our rats live to the end of their expected life span. None of our rats have ever died as a result of their detection work.”

What’s even more interesting is that HeroRATs is just one of many unique initiatives. The organization trains rats to detect tuberculosis, assist in rescue operations, and sniff out other chemicals. They also run a program named HeroDogs, where dogs are used alongside rats for landmine detection.

“Dogs and rats have complementary roles when it comes to landmine detection. Our landmine detection rats require ground that has been prepared in advance with little vegetation, whereas our dogs are able to conduct a technical survey in areas with lots of vegetation,” the Apopo team said. 

Hopefully, HeroRATs will continue to make new records in the coming years and prevent deadly landmines from claiming more lives.