Hierarchy is present everywhere in our planet, from family, society, urban construction, ecological systems to living organisms, although usually we neglect it. In the biosystem, to achieve transfer, exchange and transformation of substances and energy with extremely high efficiency and minimized energy consumption, evolution by natural selection has endowed many classes of organisms with hierarchically porous networks. Building hierarchy at multiple length periods and scales is a common strategy in nature to obtain living matter with extraordinary and unusual sets of properties that are highly desirable in a wide range of artificial materials.