Yesterday, from my window, I saw a rat running across our backyard. Rats have a tough life. Nobody likes them. We hate them, poison them, kill them in whatever way we can. At best, rats belong in our sewage system. Rats bring diseases like the plague, they eat our harvest and cause hunger. They’re vermin - basta.
But now I felt sorry for the rat in my garden and did not even tell my wife about it. She might have asked me to go outside and kill it, which I no longer will do. Not now, not in future. Because I have started to like rats.
What follows is the story of APOPO, a group of rat lovers that started a social enterprise with operations in Tanzania and Mozambique. Its founder, Bart Weetjens (Belgian), picked on the idea that the olfactory system (i.e. the nose) of rats is extremely advanced and very sensitive. In some old literature from the 1970s Weetjens’ eye fell on a story that rats can pick up the scent of trinitrotoluene (TNT), the explosive used in landmines. Given the fact that most mine-clearing processes are slow and expensive, the rat lovers thought of setting up a programme to use rats for this purpose. And with massive success (see their 2009 annual report here).
Rats go to school
The APOPO staffs are experts in training the African Giant Pouched Rat (Cricetomys gambianus) to detect mines. Young rats first undergo a phase of socialisation, where they get used to working with people. Then follows the ‘click’ phase, where display of desired behaviour is rewarded with a bit of food. If the rat does what the trainer wants, he uses a click sound to reinforce the behaviour resulting in the reward. Slowly but surely, the rats figure out that mine detection yields a piece of banana, and so turn into expert mine detectors.
Mozambique
APOPO has been active in Mozambique since 2003. Both during the independence war (1964-1974) and the civil war (1977-1992) all ten provinces of Mozambique got littered with landmines. A recent survey declared more than 12 million square metres as mined areas in 541 sites in six provinces. But during 2008-2009 the good rats already turned 440 thousand square meters into safe land again after detecting some 200 mines. By 2013 they hope to have cleared nearly a third of all mined areas. Turning dangerous land into agricultural land. And you know what? The rats do it at half the price of conventional methods ($ 1,18 per square meter). APOPO call their rodent staff HeroRATs. They sure are.
Tanzania
And the story gets better. Weetjens and his crew thought of tackling another major killer: tuberculosis (part of MDG6). They thought of detecting the specific smell of the causative organisms, the TB bacilli, in the sputum of humans. Using much the same principle of training the rats to display arrestment behaviour when they encounter some spit with the smell of TB, they have now developed it into a full programme. In 2008/9 the rats sniffed out the spit of some 46 thousand Tanzanians. What’s more, they detected TB in 561 of these samples that were not detected using microscopy. You can’t fool a rat. APOPO estimated that they averted 13 thousand TB transmissions now that the HeroRATs led to patients receiving appropriate DOTS treatment.
What’s the big deal?
First, this isn’t ‘low tech’, it is ‘no tech’. Using simple yet highly sensitive and specific approaches that are suitable for low-income countries that cannot afford expensive laboratory equipment to detect TB using PCR or other DNA-based methods, or advanced detection equipment for mines.
Second, APOPO shows us that solutions to problems in the developing world can be tackled by solutions that would not be used in the developed world. Their starting point was rural Mozambique, and thinking of solutions from 'within' rather than adopting solutions from 'outside'.
Large sums of money are being spent on the development of electronic noses for TB detection. These may come one day, but again may not be affordable for low-income countries. Or will be technologically complex and prone to faltering under harsh field conditions.
Last year a colleague of mine submitted a project to the Gates Foundation to train dogs to detect the transmissible stage of the malaria parasite in humans (the gametocyte; see life-cycle here). He didn’t get funded, but the APOPO story makes me confident that we should re-visit the idea…
HeroRATs: I love them. It's development at its best.


Arguably, the topic is little sexy but your approach and introduction made it vivid and interesting, again, nice job, Bart!
Thanks Helena. I’m all up for sexy rats!
Good one! Certainly a smart way to use this no-tech method. But I wish all of them rats could go clear minefields - after their cousins mice made my previous kitchen their home and forced me to watch them jumping in and out of the bin, running fast, making curves, slipping on the floor and finally hiding only to come out again when you least expect it, whrrr…
@Giedre. There’s always the option of becoming friends with them and train them to keep you place tidy, Ha!
In all seriousness, I really think this is a wonderful project that deserves broad attention. That’s why I decided to blog about it here. Moreover, it was time again for a positive story, don’t you agree?
Yeah definitely! I agree, it’s a great initiative, low-cost too (as you say the rats do it for just half the price of conventional methods). And of course it’s good to have some positive stories, because, as your brother put it in a comment to another post, we’re in a bigger mess than he had thought. I have the same feeling.
@Giedre. It would indeed be nice if more ‘positive’ stories would appear here. I guess the pool of ‘bad’ stories is just a lot bigger, so the search for gems is harder. But, don’t forget Ian’s positive action showing how aid is doing good…
Surprising .. This surprise me
Me too, World is full of suprising things.
@Aija, @Jan. I agree. When I heard about this the first time myself I was also really surprised. The idea is so simple once you know it. The art is to be the first to pick it up and do something with it. There’s a great quote about this regarding innovation: Innovation is seeing what everybody sees but thinking what nobody else thought. So true for this example…
Great
I am all for no-tech solutions,a nd this seems really brilliant.
This is just amazing!
@Bart, thank you so much for your thoughtful, engaging and well-researched blog post about us HeroRATs! We really appreciate you sharing our work, and send you warmest greetings from Tanzania. Karibu sana! The HeroRATs team
@HeroRATs. Thank you so much for responding to this article. I really appreciate that APOPO responds. And therefore I hope that you will respond once more and tell us about your future plans. Are you considering other diseases? Or other ways of using rats?
I found an ever better YouTube video about HeroRATS. Have a look: http://www.youtube.com/watch?v=NtPognwb13I&feature=player_embedded#!
Nice article - I love people using innovative solutions to problems. (boring video though - ha ha (private joke))
@Ian. That’s why I thought of mentioning the other video above
. I hope your attention span will cover 6 min, 39 sec (private joke)...
@bart - just about but I wavered at about 2 mins 30 - I’m a busy man.
Think it’s a quality thing. The hook is rats solving mines. Great but I know nothing of why the mines are there in the first place, what international efforts are being made around mines, what can I do as an indivdual to solve this problem. In it’s own way it’s simplistic but I don’t mind that…..ha ha!
@Ian. Please follow the links in the blog above. They link to the APOPO website where you can read everything about mines, why they got there (Mozambique), and what is done about this in terms of international efforts. You as an individual can adopt a rat (also mentioned on the site) so you can be directly contributing to this programme. Sometimes it helps to click on the links in the blogs…
Thanks @Bart. Of course, great questions. To clarify, at this stage APOPO’s tuberculosis detection program is in a research phase. Proof of principle has been provided, and we’re now focusing on working towards full implementation.
Right now, the HeroRATs provide second-line TB screening for five DOTS Centres in Dar es Salaam (covering a population of approx 500,000 people in deprived communities). And we’ve already increased the detection rate in these hospitals by over 30%! Our aim, though, is to become a first-line screen for TB - allowing for rapid case detection, with confirmation to be completed by microscopy or another technology.
Our other current main focus is expanding our demining operations into different countries (we’re building partnerships in Angola & Thailand), as well as completing clearance of the Gaza Province in Mozambique to help them become a mine-impact free country by 2014.
That said, we are in the process of looking into new and different applications for our detection rats. Some of the possibilities: security screening (at ports or airports), other health applications, or disaster recovery work. If you’d like to stay posted on our future projects, please feel free to sign up for our monthly e-newsletter at http://www.herorat.org or follow us on Twitter @HeroRATs.
Have you checked out the HeroRATs feature in The Economist on YouTube? Slideshow of our rats in action with commentary/explanation from our founder, Bart Weetjens. http://www.youtube.com/watch?v=8UcA8V_EEx0
There’s also more clips of the heroes in action on our website:
http://www.herorat.org/media/heroes-action
Many thanks again for your belief in our work, Bart! Let us know if you have any more Qs
The HeroRATs team
@Ian Sullivan - what can you do as an individual? Adopt a HeroRAT! http://www.herorat.org/get-involved/adopt-rat. It’s only 5 euros a month, and it will only take you 2 mins 30 to sign up :D
You can also find out plenty more about the landmine issue in general here:
http://www.herorat.org/why-we-do-it/landmine-issue
Or more specifically, the Mozambique problem:
http://www.apopo.org/mozambique.php
@Ian Sullivan - what can you do as an individual? Adopt a HeroRAT! http://www.herorat.org/get-involved/adopt-rat. It’s 5 euros a month, and it will only take you 2 mins 30 to sign up! :D
You can also find out plenty more about the landmine issue in general here: http://www.herorat.org/why-we-do-it/landmine-issue
Or more specifically, the Mozambique problem: http://www.apopo.org/mozambique.php
@HeroRATs. Many thanks for providing additional information about APOPO’s activities. Great video from the Economist.
One immediate question I have: will you work with African rats outside Africa? And, in terms of possible diseases being carried by the rats, how do you deal with veterinary inspections when transporting animals between countries?
Is there a suitable rat in S America (I heard Columbia being mentioned in one of the videos) or an Asian equivalent of the African Giant Pouched Rat?
I’ve been a sponsor of “Ziko”, a Herorat for a year-and-a-half after my girlfriend gave me his sponsorship as a Christmas gift. Not only do I think these rats are beautiful animals, but their relationship with their human trainers belies their intelligence and social skills.
Thanks for the article.
Isn’t it ‘coz sniffer dogs get bored? Rats have a longer attention span, right?
@Clare. I don’t think so. One issue for sure is the fact that rat training and maintenance is cheaper than dogs… but maybe HeroRATs can tell us more about this?
@Bart. Thanks for your questions! The African Giant Pouched Rat or Cricetomys Gambianus is indigenous to a large area (all of sub-Saharan Africa!) which covers a number of countries that are still impacted by landmines. As for projects in countries outside of Africa…at this stage, we plan to stick with the Cricetomys due to its long lifespan (6-8 years, providing good return on training time), calm character, and proven record in the field.
In answer to your question about vet inspections when transporting, and potential disease carrying between countries…this just involves looking into the import requirements for particular countries. We work together with the authorities to make sure all necessary precautions are taken for the health of our rats, as well as any species they may impact on the ground in a partner country. Normally our rats are disease-free, but depending on the country a short isolation period may be required.
@Michael Kucsmas - thank you for your comment! The relationship between our HeroRATs and their human colleagues is certainly an essential one, mutually beneficial and quite amazing to watch. I hope you’ve enjoyed being involved in our work via your adoption of Ziko! (Who is a superstar at sniffing out TNT, by the way…)
@Clare Herbert - actually one of the advantages of using rats is that they motivated by food, so exchanging between different handlers is simple (provided you have some tasty banana in your pocket!) On top of that, the rats are accustomed to having their nose close to the ground, sniffing around and scratching when they are find something of interest…we are simply utilizing their natural habits and training them to find something specific (TNT or TB bacteria). They are quite happy doing repetitive tasks, and easy to socialize. But the biggest advantage, as Bart mentioned, is cost - rats are cheap to feed, transport, maintain, etc - and in the developing world that means everything! It costs approximately 5,000 euros to fully train a mine detection rat (a demining dog is said to cost up to three times this).
The use of rats in this field is not meant to replace dogs or manual deminers, but they each serve as a complementary technology within the broader humanitarian demining toolbox. The real issue is how we can best work together to collectively reach the goal of a mine impact free world, in the most efficient and cost-effective way.
Thanks everyone for your interest in our work!
The HeroRATs team
@HeroRAts - really good, impressive work! I am so happy that you are looking into alternative solution, which really appreciate the power of nature we have yet to discover;)
@Bart great story, thank you ever so much for sharing!
@bart - I thought I’d come and get your attention on your blog!! Just to say that hopefully this might get you thinking more about why developing different products for different audiences is important - the aid animation got on Channel 4 News - great exposure for Oxfam and keeping us in people’s minds when they think about aid and the debate.
Maybe that means they’ll read one of our blogs that features our policy messages, or watch the animation that supports those same messages and maybe one or two might read the paper itself:
Have a look: http://www.channel4.com/news/articles/politics/international_politics/uk+aid+held+at+07+per+cent++for+how+long/3659692
Much in the same way that Hero rats might capture the imagination and get people who dont think about landmines interested!
That makes sense! Thanks for clarifying.
@HeroRATs. Thanks very much for all the clarifications! Most useful, and good luck with your work!
@Ian. That’s 15 seconds of your animation on Channel 4. Guess their attention span is even shorter…
@bart - guess so! But some of us have got to try and get messages beyond the audience of the converted…..And as we all know ‘every little bit helps’!
@Ian. Of course. I appreciate and understand. Looking at the rats - which is very specific compared to the animations you did, what do you think a ‘Rat animation’ would accomplish? In other words, not focussing on the huge and big complexity but on a very specific example? What would the impact be?
@bart - 1st question, who is the audience for such an animation - what do they know about hero rats? What do you want them to do as a result of seeing this? Donate/campaign/take on board a message
If I take the audience to be someone like myself (interested but not necessarily well informed) then if I was only going to take away 1 thing from this what would it be? ie. what is the main message you want to get across? And do you want me to donate, campaign against landmines, share the video with my friends?
If you look at the animations we did the audience in mind was Oxfam supporters (in a broad sense) so they know of aid and know that there’s debates etc (usually down the pub) we have a new aid paper with new positions -so we want to engage them and reassure them that aid can make a diffence so when they debate with their mates they feel mre confident in their beliefs (after all aid is coming uunder fire a lot at the moment)
Then - is an imation the best way of commuicating that
@Ian. Sound like you’re working on the animation already… The audience would be the general public, and as you can tell from the comments above, not many people are aware of this success story. The goal of it would be to (just like Michael) to adopt a rat, to donate a small amount online for expansion of the APOPO programme.
The simplicity of the animation in the case of rats would be to show what you can do with them (mines, TB, and potential other uses of their noses…). On top of that, it is a ‘good news’ project, likely to ‘sell well’.
APOPO has a great and informative website, so they may not need an animation on top of that. However, as in your animations, you may deliver a simplified message in just a few minutes, and generate a lot of support.
Are you game?
I can help you write a script and reccomend some animators that’ll do a great job - drop me an email .(JavaScript must be enabled to view this email address)
@Ian. Thanks for info. The HeroRATs people are following this thread, so if they like the idea I am confident that they will contact you.
The ‘Good rats’ have made it to ‘Inside Africa’ on CNN! Great job…, see http://edition.cnn.com/2010/WORLD/africa/09/07/herorats.detect.landmines/index.html#fbid=j8cysS9ntiu&wom=false