Long plagued by rats sneaking around the city, Shanghai has decided to turn to a special contraceptive to lower the rodents' population in downtown areas.

Pest control experts said it was the first time in the country that contraceptives had been used to contain the population of rats and mice in cities.

The three-month extermination program will cover some 300,000 households, companies and public places, with more than 10 tons of contraceptives to be used as bait, said Jin Peiwu, deputy director of Shanghai Municipal Committee for the Patriotic Public Health Campaign.

Jin said the campaign would be a trial, in areas like old houses, public greenbelts, marketplaces and restaurants, to compare the contraceptive's effectiveness with chemical rat poisons.

The gray contraceptive pills, "Beiao rodent poison is extracted from plants and will reduce or even stop the male rodents from producing sperm.

The pills will do no harm to humans or livestock.

Chinese used to rely on chemical rodent poison to rid their homes of rats and mice, but the problem soon returns since it takes only 20 days for a female mouse to bear a new generation.

(Xinhua News Agency October 15, 2003)