The third volume of the series "Bionics" introduces the lightweight construction principles of nature and explains how biological structures can achieve maximum stability with a minimum of biomaterial. It features natural lightweight profiles, principles of composite stabilization, as well as interesting folding principles and their technical applications. Methods of research, discovery, and invention stimulate personal creativity through the reading content and encourage the construction, crafting, and building of simple models. With the help of exciting experiments on lightweight construction, the created models can be tested, allowing for independent insights to be gained.