"So, the idea is to identify each individual squirrel, not just whether it's red, but you could say: 'That is Sally the squirrel and her dad was Ben and she travelled up to Scotland through England'.

"The whiskers are like an individual fingerprint," said Ms Mcclenaghan. "So, the idea is to identify each individual squirrel, not just whether it's red, but you could say: 'That is Sally the squirrel ...