The original head bangers, sheep have fed and clothed humans for eons thanks to a proud heritage. They’re tough, enduring, with a head for heights and totally bonkers. This is the world of sheep and goats. Nature’s biggest butt heads. Sheep symbolise rural idylls around the world, they’re a familiar site to us all, and they should be, there are plenty of them. About a billion walking balls of wool, and 900,000 of their close cousins, the goats. They have been feeding and clothing families across the world for 11,000 years. After the domestic dog, they were the first animals that we tamed. Living cheek to jowl for so long, they feel pretty familiar. But what do we really know about them?