The following is from Wikipedia but has been widely featured in the media, following the publication of an article titled “Teaching Giant African Pouched Rats to Find Landmines: Operant Conditioning with Real Consequences” in the journal Behavior Analysis in Practice in 2010:
APOPO (an acronym for Anti-Persoonsmijnen Ontmijnende Product Ontwikkeling: "Anti-Personnel Landmines Detection Product Development" in English) is a registered Belgian non-governmental organisation which trains African giant pouched rats to detect landmines and tuberculosis. APOPO's mission is to develop detection rats technology to provide solutions for global problems and inspire positive social change.
Bart Weetjens, the founder of APOPO, loved playing with his pet rats when he was a young boy. Years later, as a student at University of Antwerp, Bart applied the idea of using rodents for mine detection as an outcome of his analysis of the global mine detection problem. Due to his childhood experience, he knew that rats, with their strong sense of smell and trainability, could provide a cheaper, more efficient, and locally available means to detect landmines. Early research into this technology began in Belgium, with initial financial support from the Belgian Directorate for International Co-operation (DGIS) in 1997 to develop the concept. In 2000, APOPO moved its headquarters to Morogoro, Tanzania, following partnerships with the Sokoine University of Agriculture and the Tanzanian People’s Defence Force. Now housed by the University, APOPO trains the rats – termed HeroRATs because of their life-saving capabilities – in near-to-real conditions.
In 2003, APOPO began operations in Mozambique, with its first mine detection rats achieving official accreditation, according to International Mine Action Standards in 2004. Fully integrated mine-clearance operations began in Mozambique in 2006. In 2003, APOPO won the World Bank Development Marketplace Global Competition, which provided seed funding to commence research into another application of detection rats technology: Tuberculosis (TB) detection. In 2008, APOPO provided proof of principle for the utilization of trained rats in detecting pulmonary tuberculosis in human sputum samples. In 2010, APOPO launched a three-year research plan to closely examine the effectiveness of detection rats in diagnosing tuberculosis, in comparison to other diagnostic technologies, and to focus on future implementation models.
Using African giant pouched rats to detect landmines has several advantages. The rats are indigenous to sub-Saharan Africa, where they are used and, thus, are well-suited to the climate and are resistant to many endemic diseases. They are also widely available and inexpensive to procure. Few resources are needed to raise a rat to adulthood and they have a relatively long lifespan of six to eight years. Furthermore, rats do not form bonds with a specific trainers but rather are motivated to work for food. This adaptability allows for the trained rats to be transferred between handlers.
In the minefields, the rats are too light to detonate a pressure-activated mine by walking over it. Their small size also means that the rats can be easily transported to and from operational sites. Mine Detection Rats (MDR), the name given to the African giant pouched rats (genus Cricetomys) used by APOPO, work to detect landmines by using their exceptional sense of smell. In a minefield, MDRs wear harnesses connected to a rope suspended between two handlers. Rats methodically sweep up and down a demarcated hazardous area and indicate the scent of explosives by scratching at the ground. The insignificant weight of the rats means they do not detonate a landmine; their scratching solely indicates the presence of a mine. Each suspected area is screened by two animals. The locations that are indicated by the rats are marked off, and then followed up later by a manual demining team, who detect and destroy the mines.
APOPO is currently the sole operator for the demining of the Gaza Province in Mozambique. This will assist Mozambique in reaching their 2014 APMBC deadline. Operations in Mozambique began in 2003, with the first group of 11 mine detection rats passing official accreditation tests in 2004, and fully integrated mine clearance operations – including manual deminers, mine detection rats, and machinery for ground preparation – in 2006. Since the start of operations, APOPO’s Mozambique Mine Action team has returned over 6 million m2 of land to the population. Over 2,400 landmines have been found and destroyed.
In 2010, the Thailand Mine Action Center (TMAC) supported APOPO’s proposal to conduct a combined non-technical and technical survey of all mine suspected areas in the provinces of Trat and Chantaburi, along the Thai-Cambodian border. APOPO is conducting the project in partnership with local Thai NGO Peace Road Organization, with the goal of accurately determining how much of the suspected hazardous areas (SHAs) actually contain landmines.
Tuberculosis is one of the deadliest diseases in the world, responsible for 9.2 million new illnesses and 1.7 million deaths each year, mainly in poor countries. Rat detection technology is aiding DOTS programs to help diagnose vulnerable populations. APOPO trains detection rats to detect Mycobacterium tuberculosis in human sputum samples. In APOPO’s laboratory in Tanzania, rats sniff a series of 10 holes in a line cage, under which human sputum samples are placed for evaluation. When a rat detects TB, it indicates by keeping its nose in the sample hole and scratching at the surface of the line cage.
Currently, in most of the world, tuberculosis is detected through microscopy, a method that has not changed significantly in the last 100 years. Microscopy is relatively slow: on average, a laboratory technician can process 40 samples per day, while a trained rat can evaluate the same number of samples in less than seven minutes. APOPO’s detection rats provide second-line screening to eight partner DOTS Centers, located in Dar es Salaam and Morogoro, Tanzania. In 2010, this second-line screening increased new TB case detection rates of APOPO’s partner hospitals by 43%. In the future, APOPO hopes detection rats will become a key instrument in curbing the spread of Tuberculosis worldwide. Exceptionally fast, accurate, and cost-effective, they have an important role to play in screening large and at-risk populations.
Full training of a detection rat takes approximately nine months on average, and is followed by a series of accreditation tests. The rats are socialized and then trained through principles of operant conditioning. When the rats first begin their training, they learn to associate a “click” sound with a food reward of banana or peanuts. Once they learn that "click" means food, the rats are trained on a target scent. Rats trained to detect mines are taught that when they indicate TNT (the explosive in most mines), they will hear a click and then get food. The rats working on TB detection are trained using TB-positive samples. After various stages of training which build on the skills learned in the previous stage, the rat is ready to go to work in either a minefield or into the research lab for tuberculosis or remote scent tracing (RST) detection.
Editor’s note: Many thanks to Stella Larson for bringing this material to our attention.