Guardian: China’s authorities have scattered 200kg of rodent contraceptive pellets across the Tibetan plateau to control what they describe as a “plague of desert rats”. The growing number of rodents have been blamed for destroying fragile high-altitude grasslands and accelerating the spread of deserts. Biodiversity experts warn, however, that the extermination campaign could worsen the problem of soil degradation and the poisons could damage other parts of the plateau …