Couple boxes from IKEA, drill and some hooks from 3D rptinter and you could start your own earthworm "bussiness".Key to success of this construction is in sizes and amount of holes.From the ground: First box without holes for capturing "water", it's perfect fertilizer. Second box with 3-5mm holes at the bottom, only to release moisture and hold material and worms inside. Last two boxes 10mm holes everyvere for enough air, worm tunnels and slow shift of material down the way.Hooks are printed in PLA for outdook use and UV stability.