Even in China, where staggering statistics are commonplace (1.3 billion people, $1.3 trillion in foreign reserves – they trip off the tongue), 2 billion is an awful lot of field mice.
That, according to local newspapers, is the number of small furry rodents currently plaguing the shores of Dongting Lake, munching their way through everything they can find after having been flushed out of their nests by the lake's rising floodwaters.
Just who estimated the mouse numbers is unclear. Nor, presumably, has anybody counted each one of the 2.3 million mice said to have been killed in Hunan province over the past fortnight by smacks with a shovel, poison, or traps.
Mr. Yi, a local government official in Lujiao, reports that poison is preferred in his village because it is the most effective. "I have never seen so many mice," he says in a telephone interview. "There are dead mice everywhere, in the front yard, the backyard, the courtyard. Because it is warm now they smell – I am collecting them up in big bags and burying them."
The swarms of voracious animals – said by eyewitnesses to have turned whole hillsides black with their presence – recall stories from the Bible. But they are a signal less of heavenly wrath than of man's carelessness, according to environmentalists.
Though a prolonged drought apparently favored field mouse reproduction this year, and though mice are a constant menace to rice farmers in the region, their numbers have rocketed recently because they have fewer and fewer natural predators.
Snakes and owls are increasingly rare, local residents say. That is partly because over-exploitation of the rich farmland around the lakeshore has depleted their natural habitat, and partly because a lot of Chinese diners regard them as delicacies.
The snake trade "has become a lucrative business," according to the state-run China Daily newspaper, especially in the neighboring province of Guangdong, where citizens are renowned throughout China for eating anything that moves.
"Owls have suffered the same fate," lamented a recent editorial in China Daily. "Some believe eating owls is a good cure for headaches." But each sweet-and-sour owl on the table means 1,500 more field mice that the bird has not eaten as prey each year.
Now come reports that Guangdong's adventurous gastronomes have seized on Hunan's hardship as an opportunity: They are said to be skipping a link in the food chain and eating the mice themselves.
The Information Times, a newspaper based in Guangzhou, the provincial capital of Guangdong, reported that trucks from Hunan had been seen delivering crates of black market mice by night to an illegal wild animal market in Guangzhou.
Mouse is turning up on restaurant menus in nearby cities, the paper reported.
The reports have alarmed health officials. Guangzhou's wild animal market is illegal for a reason: Scientists are convinced that SARS, Severe Acute Respiratory Syndrome, first broke out in humans in Guangdong, among people who had eaten wild civet cat.
Since then, cooking and eating wild animals such as field mice has not been allowed.
Meanwhile, back at Dongting Lake, the floodwaters are receding after the worst summer floods in central China for 50 years killed over 400 people and forced 3 million to evacuate their homes.
Residents hope that as their houses dry out, so will the mouse holes, tempting the creatures to return to their normal habitat around the lake. And the Guangdongese will have to find something else to eat.