Scientists in the US have mimicked the structure of bird nests to overcome the extreme fragility of highly insulating aerogels. Already used to protect NASA's Mars rovers' delicate electronics from the cold, aerogels are low-density materials prized for their insulating properties. However, the porous materials, made of interwoven nanoparticle strands, are also extremely fragile, limiting their use. Now Nicholas Leventis and colleagues at Missouri University of Science and Technology, Rolla, have made a stronger material by boosting the interlocking between strands. Aero gels are typically made from interwoven strings of silica nanoparticles, and can be strengthened with a polymer coating, so that the strands form crosslinks wherever they meet. But inspired by the highly interlocked structures of bird nests, Leventis switched to vanadia-based structures, which form a more highly entangled worm-like nanostructure. These materials are multifunctional in character namely strength in combination with acoustic and thermal insulation - such as lightweight structural materials for buildings, and the automotive and airplane industries.