Ben Hay makes Tree Thump Didj. Co.'s didjeridus using a split-and-hollow method, which gives him precise control over the internal shape and sonic characteristics of each instrument. Tree Thump Didj. Co. uses only fallen and dead-standing timber, so living trees are never harmed in our crafting process. Click the picture above to see a slideshow of each step involved in making a split-and-hollow didjeridu.