Cape wagtail.

These little birds fascinate me, always busy and purposeful, they have very little fear of humans and can become quite tame. A friend of mine once had a pair nest in a fern he had on a stand in his lounge. While they were hatching their eggs, then feeding the nestling's, until they fledged he had to leave a window open. 

Cape Wag-tail. Took this photo late this afternoon.