By Francis Markus
BBC correspondent in China
An explosion of gerbils is decimating vast areas of grasslands in China's north-western Xinjiang region, with some of the prairies completely destroyed by hundreds of rodent burrows, according to authorities in the region.
The gerbils running riot in China's arid far north-west may sound like the fluffy pets loved by so many children but they are in a different league.
The Great Gerbil found in many parts of Central Asia can be up to 400 millimetres (16 inches) long from head to tail.
With its short fur and large genitals, it is the member of the family most resembling the rat.
Officials say the gerbils have damaged more than 4m hectares (11m acres) of grassland about the size of Switzerland.
This is reported to be the worst rodent disaster to hit this region of Xinjiang in 10 years.
Authorities are trying to combat the gerbils, not only by using poison, but also by breeding eagles to devour them.
Unless they succeed, the damage the rodents are doing could add to the steady encroachment of the desert, already occupying a vast part of the region.