@Oompoofishy they are just birch leaves and bark from our garden. The bark is mold resistant and the leaves are dead ones pulled off that haven't fallen yet. Only stuff I bake is rocks from the beach just to get rid of any microorganisms but the vast majority of my specimens are wild caught so a few tiny specs of mold won't do them any harm. I've even accidentally introduced wild springtails before which was really beneficial
@Ungoliant won't be doable once she puts a web mat down, the silk is like elastic!