The pack of mutant black squirrels that are giving Cambridgeshire's grey population a taste of their own medicineLast updated at 15:13pm on 25th April 2008 Mutant 'testosterone-fuelled' Russian black squirrels in Cambridgeshire are giving their grey cousins a taste of their own medicine and driving them from their homes. A Cambridge academic believes the unusual black squirrel now makes up half of the total squirrel population in the area from which they have originated. The upstarts are the genetic mutations of grey squirrels. And although nuts may be their food of choice there have been reports of their hungry...