Chris Sperring this week joins Dr Fiona Mathews, Senior Lecturer in Mammalian Biology at Exeter University on a quest to unravel the secrets behind one of the most abundant if secretive mammals in the UK – the vole. At nearly 1000 feet above sea level, the Mendip Hills is a hotspot for both field and bank voles and as Chris and Fiona set out to see a vole for themselves it proves much harder than they think. Despite an estimated population of 75 million field voles in the UK these animals lead a precarious and all too brief life. Living for just a few months voles are prolific breeders and populations can fluctuate up to tenfold on a three to four year cycle which can have drastic effects on the species which prey on them including arguably Britain's most loved bird, the barn owl.