In Man vs. Rat, the Humans Get a New Edge

A modest advance in rat-catching technology is improving people's lives in rural India.

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This is a story about how the development of a better mousetrap—more like a rat trap, actually—is helping some of the poorest of the poor in India, raising their incomes and so enabling their children to go to school.

Chinnapayan Krishnan, 41, is a rat exterminator. He belongs to the Irula community, a low-caste tribe that for many centuries has provided the rat catchers in India's southern Tamil Nadu state. Local farmers hire the Irulas because rats can consume up to a quarter of their crops. For Krishnan and others, rat catching is both their source of modest income—the equivalent of 5 cents a rat—and a key source of food. Rats may provide most of the Irulas' meat and grains (recovered from rat burrows), usually consumed at one meal per day.

Wiping sweat from his brow, Krishnan stands with his rat-extermination paraphernalia on an arid patch of farmland. In a hushed tone, he asks everyone around to be still. "They can sense us," he says softly, pointing at the spot where a rat has burrowed nearby. "They are very clever creatures." Krishnan plugs two nearby ratholes with dirt, blocking possible escape routes. Then, using a rudimentary-looking device, a metal drum with a hand-operated air pump, he blows a torrent of smoke into the burrow. Seconds later, Krishnan reaches in and pulls out a stunned, mangy rat by its tail.

This, believe it or not, is progress. For the Irulas, a disenfranchised community of 3 million people, even simple technology can improve their lives. For ages, Irulas have relied on a traditional fumigation technique: Rats are caught by lighting a fire in a clay pot that covers the mouth of a rat burrow. The rat catcher physically blows air through a small hole in the bottom of the pot to send the smoke into the rat burrow. The rats are retrieved unconscious or dead. But this method is inefficient and hazardous. More than half of the time, the targeted rats manage to get away before being overcome by the puffs of smoke. The Irulas often suffer burns, and smoke inhalation leads to respiratory and cardiac disease. For this and other reasons, Irulas are believed to have a life expectancy of just 45 years.

A few years ago, a Chennai-based nongovernmental group, the Center for Development of Disadvantaged People, designed a smoke-producing device that incorporates a hand-operated air pump, which forces a greater volume of smoke into burrows more quickly than possible using the traditional clay-pot technique. The device both speeds the job and makes the process less hazardous by reducing the rat catcher's smoke exposure. The World Bank recognized CDDP’s achievement with a Global Development Marketplace award and a $98,500 grant to provide the device (made locally) to over 4,000 Irula families in Tamil Nadu villages like Sirigumi, which lies 50 miles from Chennai.

One step at a time. The impact has been remarkable. Krishnan has quadrupled his daily catch to as many as 20 rats, increasing his daily earnings to $1 from 25 cents. For the Irulas, who have a literacy rate of just 1 percent, even that small amount of extra money means they can afford to send their children to school instead of putting them to work. "The Irulas are a great example of how bringing technology to the rural poor can help them improve their lives one step at a time," says Siri Terjesen, a professor at the Neeley School of Business at Texas Christian University in Fort Worth, who has visited the Irulas to study the impact.

No less significant, perhaps, this modest rural innovation has brought a sense of pride to a people characterized as "untouchables" for their lowly caste status. "Everyone wants to abandon their lives as rat catchers—a miserable existence that only brings shame," says Krishnan. "But this rat trap gives a sense of hope to our community that we, too, can have productive lives."

But even at a cost of just $25 (versus 50 cents for the traditional clay pot), the device is out of the reach of most Irulas. CDDP Director Sethu Sethunarayanan says he hopes the Irulas will be able to obtain microcredit loans to afford the devices. With over 100 million small farmers in the Tamil Nadu and neighboring Andhra Pradesh states, this kind of technological advance is in great demand. Farmers around Sirigumi prefer using rat catchers rather than poisons, which they know can hurt soil productivity and pose a risk to animals and humans.