On the southern edges of the Ethiopian Highlands, the towering spires give way to grassy moorlands which are home to the rarest of all African predators - Ethiopian wolves. Like their European ancestors they patrol vast territories and live in tight family groups. But otherwise, they're quite different. Small and fine featured, they've given up chasing animals in large packs. Instead, they've evolved to become specialist rat catchers. Nimble legs, sensitive ears and narrow muzzles are the tools of their trade. A specialist hunter like the Ethiopian wolf is quite capable of finding rich pickings alone. Giant mole rats are much bigger and therefore more highly prized prey. These timid creatures are justifiably afraid to leave their burrows and scan for danger as if with periscopes. But they're up against experts. Wolves can stalk up to the burrow undetected and will then wait patiently for an opportunity to pounce. There's no shortage of food up here - rat infested hardly begins to describe a place where there are 2 tonnes of rat per square kilometer.