John Heard, whose sheep graze on Dartmoor, had lost 200 over the past few years to thieves. That was before he dyed the whole flock orange. He hasn’t lost a single sheep in the year since. So perhaps the notion of dyeing is the way to do it. Orange is a repellent colour – drivers of orange cars must be able to leave them unlocked. To make up for the visual effect, Mr Heard might think of seeking sponsorship from some mobile phone company or economy airline.