A walker was gobsmacked when he out on a stroll and appeared to spot a herd of cows grazing on the roof of a bungalow. Ian Wilson, 46, was on a walk in Newton Abbot, in Devon, when he thought he saw the cows on top of the slated roof next to the chimney. But on closer inspection, he realised that it was in fact an optical illusion and the animals were in the field behind.