Climate change and land-use pressures destabilise invertebrate populations not only at landscape scales but also within the microclimates of soil and near-surface habitats, where small variations in humidity, shade or airflow can critically affect survival. Existing insect hotel strategies typically rely on structurally stabilised, long-lasting materials and homogeneous cavities, privileging cavity-nesting bees while offering limited support for moisture-dependent decomposers such as litter-dwelling and soil-surface invertebrates that depend on organic substrates and buffered humidity. This paper introduces a multiscale design experiment that explores how designed porosity could engage moisture-dependent invertebrate ecologies. The prototype combines a gyroid-type triply periodic minimal surface fabricated from post-consumer eggshell waste with a moisture-retentive mycelium material layer, forming a time-evolving porous column. Outcomes from an initial 48-day field deployment are analysed through observations of fungal colonisation, material erosion and faint scraping marks interpreted as indicators of ecological engagement rather than habitat performance.