Tuesday, November 9, 2010


Their Nose Knows


Usually when one thinks of rats, they either picture a dirty disease-spreading rodent in a sewer or clean white lab-rats used for experimentation. However, Bart Weetjens, the founder of APOPA, a Dutch non-governmental organization working to train rats to help detect TNT in landmines, is hoping to change this perception. Weetjens considers the rats he trains to be heroes.

Currently, it takes de-miners an entire day to clear a 200 square-meter plot of land in Mozambique of hidden land-mines in order to re-open the land for use. However, with the use of trained rats, a field of the same size can be cleared within two hours. According to Weetjens, rats are “very effective” and have “very high success rates” when it comes to the detection of explosives. How exactly are the rats trained to perform such a difficult task? The answer is Pavlovian conditioning.

Training of the rats begins at four weeks of age and starts with the mere exposure of these small rodents to human contact. Once they have become habituated to human contact and interaction and are no longer afraid of people and new surroundings, they are trained to associate a clicking sound with food. This is done by simply making the sound each time the rats are fed. Once the rats are trained to associate the click to the reward of food, they are trained to distinguish the scent of TNT from other smells. When they correctly distinguish the smell of TNT, they hear the clicking sound and are rewarded with a food treat, such as a piece of banana, thus reinforcing the link between TNT detection and food. Within 9 months, the rats are ready to move to the field and begin detecting land-mines, which can be deactivated and safely removed by workers.

Because rats have a natural ability to detect scents and are easy to train, they make the perfect animal for the job, much more effective than mine-sniffing dogs. Weetjen is confident that the future for these so called “hero-rats” is bright. He believes that rats can be trained and used in similar situations to sniff out narcotics or to search for survivors of disasters such as Earthquakes or collapsed buildings.

- Posted by Amanda Grafstein

4 comments:

  1. I never knew that rats had a keen sense of smell like that! How are they more effective than dogs? Certain species like the bloodhound are bred for hunting and tracking things by scent. Rats on the other hand aren't known specifically for their sense of smell. What makes them better at sensing land-mines? Is it their whiskers or their small body size in conjunction with their sense of smell that allows them to be more effective in TNT detection?

    Abbie Lamarre-DeJesus

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  2. According to the article, there are several reasons why rats are more effective than dogs. Most importantly, they have a superior sense of smell than dogs. Also, researchers have found that because rats are so much lighter than dogs they are much less likely to accidentally set off the mines. Also, dogs are more easily distracted and excited when they are rewarded for detecting a land-mine.

    - Amanda

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  3. Rats are pretty cool. They would be far more helpful than dogs solely for the fact that they are so much smaller- fit into smaller places, easier to carry, easier to hide, maybe less conspicuous. Is their sense of smell better than a dog's though? I would think that because dogs can have much longer noses, they would have more neurons to pick up scents, but maybe a rat is just as effective.

    -Meghan Nichols

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  4. This is really awesome. Hopefully this will change people's perspectives o rats because they really are neat little critters. Also whoever though of using Pavlovian conditioning on rats is pretty brilliant!

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