The world's biggest exporter of rice now faces a serious threat: rodents. Peasants, struggling with the country's hard hit economy, are breeding Nutria coypu , or beaver rats, in a bid to make money selling their meat and fur. But ecologists fear that the get-rich-quick craze will eventually end in an environmental disaster and perhaps, also a financial fraud.

These humble and water-loving animals were introduced three years ago by a Taiwanese businessperson. They are almost as large as a medium-sized dog and look like huge rats with webbed feet and strong front teeth. These creatures are at home in the marshes and swamps and feed on all kinds of vegetation. Promoters, enthused by the Nutria's amazing breeding capabilities, have introduced it in various parts of the world over several decades. The problem is that there is not much of market for Nutria meat or fur. And when they cannot be sold, the farmers often turn them loose, usually into swampy areas where these animals wreck havoc on the local vegetation. This means that the millions of hectares of Thailand's paddy crop face an imminent threat.

The perils of Nutria breeding became evident during the 1930s in Louisiana, usa . The farmers, seeking a way to beat the great depression, imported Nutria, hoping that the animals' brown-and-grey fur would become popular with the public. Now, Nutria has overrun Louisiana and has achieved the status of a national pest. Their voracious hunger has denuded marches and their burrows have weakened bridge supports and levees.

Thailand, too, might be facing a similar future, warn experts. The total Nutria population in the country has just touched the one million mark. Thai government, desperate to end the Nutria menace, recently issued a statement trying to persuade the farmers against their breeding, warning them not to be misled by the promoters and advertisements promising easy money.