On Colombian minefields, rats may become man’s best friends


Rats may soon become heroic figures in this nation’s struggle to detect and dispose of land mines.

Early next year, anti-narcotics police will begin deploying squads of rats to sniff out land mines in remote areas of Colombia where leftist rebels and drug traffickers have planted hundreds of thousands of the deadly devices. It’s an unconventional initiative in a country that is second only to Afghanistan in the number of land mine victims.

Using a project in Tanzania as a model, Colombian scientists have taught rats to detect mines buried as deep as 3 feet. The rats are conditioned to search and burrow down for explosives in exchange for the reward of sugar.


The rebels, principally the Revolutionary Armed Forces of Colombia, or FARC, planted the mines to defend encampments from soldiers and coca plantations from peasants hired to eradicate the crops. Coca is the base material of cocaine, which is a major source of revenue for the FARC.

Last year, 695 people were killed by mines in Colombia, 56 of them children.

Rats have the advantage over bomb-sniffing dogs of being so light that they do not detonate explosives, as canines sometimes do. And researchers have found that the rodents are more adept than dogs at sensing explosives when the materials have been masked with coffee grounds, feces, fish, mercury and other substances.

“The more I work with rats, the more I am amazed at what they can do,” said Luisa Fernanda Mendez, a civilian behavioral veterinarian in charge of the rat-training project.

Like dogs, the rodents can be trained to obey commands such as “search,” “stop” and “let’s go.” But rats, being less social than other creatures, are not as likely to be distracted by other animals in the countryside.

Using rats in place of dogs also makes sense from an economic standpoint, with seven rats costing about one-tenth what the police spend to maintain one bomb-sniffing dog, Mendez said. (Not to mention that not many people care whether a rat dies, Mendez said.)

After enthusing about rats’ abilities, Mendez was asked about downsides. She said the main one is the revulsion they inspire in most people. So police have no plan to use them in airports, public buildings, checkpoints or meeting places, where the search for bombs involves human interaction. Dogs will keep those jobs.

“We see rats working just in minefields for the time being,” Mendez said from her laboratory in north Bogota, where several kittens were running around. The cats were there so the rodents would lose their fear of them and become less prone to getting spooked when working in minefields.

Even as the numbers of land mine victims have declined in Colombia from the 1,183 killed or wounded in 2006, the toll on manual eradicators has soared as the mines have become harder to detect and rebels have planted them in greater quantities in and around coca crops.

The toll on eradicators, who for the most part are unemployed peasants or poor farmers, has risen so fast that the Colombian Campaign Against Mines, a civil society group based in Bogota, has called for the suspension of the teams.

Director Alvaro Jimenez said their use is a violation of a 1977 treaty signed in Ottawa that requires governments to do everything possible to keep civilians away from the risks of minefields

The Colombian government’s hope is that the rats could make the operations safer.

Asked whether other creatures had been considered for the job, Mendez said rats were chosen over other “small mammals” because they can be bred easily and in large numbers in laboratories.

Furthermore, rats have a highly developed intelligence that has enabled them to survive despite “being the most preyed-upon animal in history,” Mendez said.

“They even train their babies to perform their jobs, which saves us a lot of time,” Mendez said. “Rats also concentrate better than other mammals to solve problems. They want their reward.”

Kraul is a special correspondent.