Rodents have been accused of causing everything from plague to electrical fires - now climate change can be added to the list.
Two new studies have found that the Arctic ground squirrel and the beaver are contributing far more to global warming than previously thought.
The first study, by the Woods Hole Research Centre in Massachusetts, reveals that Arctic squirrels are aiding release of the greenhouse gases methane and carbon dioxide by melting the permafrost that has kept dead animals and vegetation preserved underground for years.
They do this, in part, by warming the frozen soil when they dig burrows, accelerating the melting of the permafrost.
Their faeces and urine further contribute to the process, fertilising the soil, which nourishes the microbes that create methane by decomposing the dead organic matter.
