🪱 Earthworm Bioturbation Wormery: Burrow Network, Litter Burial and Soil Mixing Coefficient

A glass-fronted wormery where earthworms are persistent random walkers: they dig burrows, carry layered sand and leaf litter along their paths and mix the soil like a diffusing tracer. Measure the biodiffusion coefficient from the mean-square displacement and compare it with the kinetic prediction.