ProductOntwikkeling or Anti-Personnel Landmines Detection Product Development) as an NGO the following year--APOPO would train and employ the Giant Pouched Rat, a common African rodent, in landmine detection. The attractiveness of rats for land mine detection was that they were light enough in weight not to set off a landmine even if they walked over one. APOPO rats would not have to be sent on suicide missions or be made into Kamikazes.       

Lara: Are dogs more intelligent than rats? What advantages do rats offer over dogs in landmine detection?

Mr. Weetjens: Rats may be more “mechanical” than dogs, and therefore, in some sense, less “intelligent.” But this difference does not adversely affect the landmine detection capabilities of rats because landmine detection is a mechanical process.

As for the smelling capacities of rats for explosive targets versus those of dogs, nobody has yet been able to quantify them. It is clear from experience, however, that the smelling capacities of both rats and dogs are sufficient to detect vapor from buried landmines. But one clear advantage of rats is that because of their smaller size, their
Lara: What's new about APOPO and how did you get the idea?

Mr. Weetjens: While previously heavy machinery and sometimes dogs were used to detect landmines, APOPO pioneered the use of rats for landmine detection. The idea of experimenting with rats first came to me when I read about olfactory (smell-based) discrimination of explosives by lab rats in American scientific journals. In the 1990s, I visited countries where landmines were taking the lives of unsuspecting women and children almost every day.

For example, women were often severely injured while collecting firewood and doing other daily chores. Though international agencies were searching for solutions to the landmine problem in order to protect such vulnerable women and make it safe for aid workers to bring supplies to people in conflict-affected areas, all their solutions relied upon expensive foreign technologies and machinery which poor nations in Africa could barely afford.

I knew there had to be a locally-based alternative and I set-out to find a solution that would fit the African context. In 1997, I initiated a feasibility study and based on its positive findings, established APOPO (Anti Persoonsmijnen ontmijnende
nose is always close to the ground even if their head is raised. The highest vapor concentration and lowest wind speed are found close to the ground, thus increasing the chances of a rat’s accuracy. Moreover, another important advantage of rats is their relative independence from a personal handler. Generally, rats show no significant difference in performance when taken over by somebody else in the absence of their own handler (of course, the new handler would have to be briefed before-hand about the behavioral characteristics of the specific rat). Rats are also preferred over dogs because the heavy weight of some dogs would be enough to set off a landmine. Overall, however, rats and dogs can play complementary roles.

Lara: How do you train rats? How long does it take to train a rat? What is the working life of a rat once trained? Does the rat need re-training from time-to-time?

Mr. Weetjens: Rats are trained by a  The combination of click training and food rewarding. In rat school, training starts at the
age of five weeks when juveniles are weaned from their mother. At first, the animals are taught to associate a click sound with a food reward. Then they have to perform certain tasks (e.g., identify an odor) to get a food reward.

After odor imprint, the complexity of their tasks is gradually increased and real life conditions are created. Food provides a strong and controllable source of motivation and an effective drive for performance. The total training schedule and time for landmine detection is half an hour per day, five days a week, for six to ten months. After a rat graduates from training school, it can begin to work in the field. The working life of a rat is up to seven years (their total lifespan being six to eight years).

Lara: Are rats given treats when they find a landmine? If so, what stops them from indicating that they have found a landmine even when they haven’t?

Mr. Weetjens: Yes, rats work for food and look forward to their treat, mainly consisting  of bananas and peanuts. Fortunately, (unlike humans!) rats do not generally cheat—they do not lie that they have found a landmine just in
order to get a treat. If poorly trained, they can, of course, make mistakes.

Lara: Do your rats periodically overlook or miss landmines? Are some rats less trustworthy than others?

Mr. Weetjens: I would not say that some rats are inherently less trustworthy than others. The quality of training can, however, account for differences in how well they perform their work. APOPO takes its training responsibilities very seriously and has strict and frequent quality checks. Rats also have to pass a rigorous test before they can graduate from training school. And if a graduate begins to under-perform in the field, that rat must return to training.

Lara: How do you make absolutely sure that the area cleared by the rats is 100% safe?  Who is the first to tread on the area cleared by the rats?

Mr. Weetjens: Once trained, rats can reliably carry out repetitive tasks. Mine Detection Rats are tested and accredited according to International Mine Action Standards, which provides them with a license to work for 6 months in a suspected area. This external accreditation test is done again every half year, to guarantee the quality of the animals’ performance. APOPO also checks the performance of the animals through daily tests and quality control measures. APOPO field supervisors check that all rats and their handlers are performing to the highest standards.

The overall reliability of clearance is reached by a   combination of different tools: mechanical devices clear the bushes on an area, then rats rapidly screen the area, and indications are followed-up by manual deminers. The combination of different tools generates sufficient information on which the authorities base themselves to release an area. Once a field is cleared of landmines by the rats, APOPO signs-off with the government, who certifies the safety of the field. Then anyone can walk on it.

Lara: What are the key challenges APOPO faces?

Mr. Weetjens: Still the acceptance of a new technology (in the shape of a rat!) is poor. Even if we provide solid evidence on the quality and cost-effectiveness of our approach, the humanitarian demining industry is quite conservative in the adoption of novel techniques. The support of this industry is needed to convince the donors to fund APOPO. However, this is a question of time. As we produce tangible results on cost efficiency, and as donors are keen to get the best clearance rates for their buck, I anticipate a growing acceptance in the donor community.

On the side of the African governments, there is a clear acceptance. The Mozambican government has tasked APOPO with the entire Gaza province in South Mozambique, and 11 Great Lakes Region countries have endorsed APOPO technology to clear mines on their common borders. APOPO has a freely releasing of intellectual property (IP) strategy, which shares the ownership of the technology and empowers local communities.

Lara: How can my friends and I help?

Mr. Weetjens: You can connect to APOPO by adopting one of our HeroRATS. It is a fun program. For only a few dollars per month, you receive letters from your rat!

Check it out at