Termites inhabit complex underground mounds of intricate stigmergic labyrinthine designs with multiple functions as nursery, food storage and refuge, while maintaining a homeostatic microclimate. Past research studied termite building activities rather than the actual material structure. Yet, prior to understanding how multi-functionality shaped termite building, a thorough grasp of submillimetre mechanistic architecture of mounds is required. Here, we identify for Nasutitermes exitiosus via granulometry and Fourier transform infrared spectroscopy analysis, preferential particle sizes related to coarse silts and unknown mixtures of organic/inorganic components. High-resolution micro-computed X-ray tomography and microindentation tests reveal wall patterns of filigree laminated layers and sub-millimetre porosity wrapped around a coarse-grained inner scaffold. The scaffold geometry, which is designed of a lignin-based composite and densely biocementitious stercoral mortar, resembles that of trabecula cancellous bones. Fractal dimension estimates indicate multi-scaled porosity, important for enhanced evaporative cooling and structural stability. The indentation moduli increase from the outer to the inner wall parts to values higher than those found in loose clays and which exceed locally the properties of anthropogenic cementitious materials. Termites engineer intricately layered biocementitious composites of high elasticity. The multiple-scales and porosity of the structure indicate a potential to pioneer bio-architected lightweight and high-strength materials.

白蚁栖息在复杂的地下土堆中，这些复杂的迷宫设计具有多种功能，如苗圃、食物储存和避难所，同时保持一个稳态的小气候。过去的研究研究了白蚁的建筑活动，而不是实际的材料结构。然而，在了解多功能如何塑造白蚁建筑之前，需要彻底掌握土墩的亚毫米机械结构。在这里，我们确定了Nasutitermes exitiosus通过粒度测定和傅里叶变换红外光谱分析，与粗淤泥和未知有机/无机成分混合物相关的优先粒径。高分辨率微型计算机 X 射线断层扫描和显微压痕测试揭示了细丝层压层的壁图案和包裹在粗粒内部支架周围的亚毫米孔隙度。支架几何结构由基于木质素的复合材料和致密的生物胶结性 stercoral 砂浆设计而成，类似于小梁松质骨。分形维数估计表明多尺度孔隙度，对于增强蒸发冷却和结构稳定性很重要。压痕模量从外壁部分到内壁部分增加到高于松散粘土中的值，并且局部超过人为胶凝材料的性能。白蚁设计了具有高弹性的错综复杂的分层生物水泥复合材料。该结构的多尺度和多孔性表明具有开创生物建筑轻质和高强度材料的潜力。