In the animal kingdom, rats are a species with an image problem. Capable of spastically scurrying in any direction, they are associated with Halloween and may elicit screams when they catch humans by surprise. Contrary to reputation, these rodents are actually very sociable, keenly intelligent and can be trained to interact with people. I recently learned that they can also be trained to work in life saving programs.
Bart Weetjens owned hamsters and rats as a boy growing up in Belgium. He carefully studied rodents’ behavior. As a young teen he entered a Dutch cadet school, but found the discipline and military philosophy conflicted with his beliefs. His family hosted African exchange students and he learned about the horrific civil wars in their home countries. After a brief stint in the corporate world, product engineer Weetjens met a Dutchman who changed his direction completely. They had a conversation about a study proving that gerbils had an acute ability to detect explosives through smell. Weetjens recalled the horror stories he heard from the African students about the land minds in their countries killing civilians. Connecting the dots like a Hero Rat on the trail of some new discovery, the young man theorized that rats with their incredible sense of smell could do everything gerbils could do. He knew rats were more social, smarter, and more easily directed with food incentive, and suspected they could be trained to detect land minds. He explains, “I knew I wanted to improve the circumstances of vulnerable communities in a way that was sustainable”.
For two years Weetjens tested his hypothesis with rats in a Belgium laboratory. Weetjen’s organization APOPO (Anti-Personnel Landmines Detection Product Development) is now based in Tanzaniam, Africa, and received its first grant to work in Mozambique. In Mozambique landmines are scattered over hundreds of miles, many near roads and foot trails, and these lethal mines continue to claim lives after the decades-long civil war. The mines choke economic development as villagers fear using the land for agriculture and cattle grazing.
There are over 8 million land mines buried in over sixty countries. Every day over 50 people, many of them children, are killed or injured by land minds. A trained rat costs about $2,000, which is $10,000 less than a mine-sniffing dog. Due to their small size they are easy to transport. Rats in captivity live for up to eight years.
How are the rats trained? Through positive reinforcement “clicker training”, a clicking device is operated paired with a treat such as a peanut or banana slice when the rat performs the required act. The rats then respond to the clicker alone. Rats are conditioned to TNT odors, trained to walk on a leash, and the leash is attached to a bar that moves toward the suspected area. When they smell explosives, the rats scratch or bite at that location. Due to their small size they do not trigger the mine.
An APOPO worker explains how the rats work in the field. “The rats are attached to their handlers via a measuring tape that is attached to the handlers’ boots. When a rat locates a mine, it indicates by scratching on the ground. The handler will note the position by writing the location on a plastic stake, which he sticks in the gound. The area will be checked by a manual deminer with a metal detector. If a mine is found, it will be safely detonated with a demolition charge.”
What’s next for these amazing creatures? Tuberculosis detecting rats are now in the research phase at APOPO. Every year almost 2 million people die from tuberculosis. Rats more accurately detect tuberculosis than standard testing, and do a day’s work of skilled technician in just seven minutes. The APOPO program detected 2,400 cases so far in Tanzania, an amazing feat that potentially prevented the spread of this contagious condition to 24,000 people. For this medical operation, the rats begin socialization at 3 weeks of age. They are extensively handled, exposed to a variety of sights and smells, go for car rides, listen to music and see other animals. The process makes them gentle and easy to handle. To learn TB detection, they are placed in a metal chamber with a hole in the center. Researchers place TB positive sputum samples beneath the hole. The rats are rewarded with favorite foods when they poke their noses in the hole, but not rewarded if they poke through a hole with a neutral sputum sample. Operant conditioning molds the rats’ behavior.
The story of the Hero Rats in Africa is spreading. Many You Tube videos show their dramatic effort. Next this humanitarian program goes to Angola and Thailand, and these tiny animals will save more lives.


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