1. Design from adult size — then inspect the juvenile gaps
Check door seams, cable ports, lid corners, ventilation slots and any gap created by a custom insert. The smallest life stage you plan to house sets the containment standard. A decorative panel should never create a hidden route behind itself that you cannot inspect.
2. Reserve moulting space before adding decoration
Many insects need to hang freely while moulting. Arboreal spiders may build retreats near the top of the enclosure. The safe design move is to mark a clear “moult zone” first and keep permanent shelves, thick branches and hard edges out of that space.
For stick insects, the Australian Museum recommends enough hanging space for a nymph to suspend roughly three body lengths above the enclosure floor or obstruction while moulting.
3. Moisture and ventilation have to work together
High humidity and wet substrate are not the same thing, and neither is useful if the enclosure is stagnant. Match moisture to the actual species and life stage, then make sure air can move through the enclosure without creating escape-sized openings.
For custom work, this often means keeping vents clear, avoiding full-wall inserts that seal off airflow, and using removable panels rather than permanently trapping damp substrate behind scenery.
4. Burrowers need structure below the pretty part
For burrowing cockroaches, tarantulas and scorpions, substrate depth and stability can matter more than the visible landscape. Heavy rocks or thick resin pieces should not sit unsupported on loose substrate where an animal can excavate beneath them.
A better custom solution may be a lightweight false rock attached to the enclosure wall, a burrow starter with a stable base, or a removable hide that gives the keeper access without collapsing the retreat.
5. Give yourself a maintenance route
Plan how you will add food, remove leftovers, refill water, trim plants and inspect the animal without dismantling the habitat. For venomous or defensive arachnids, design around tool access and containment rather than routine handling.
6. Micro scenery should be thinner than you think
A 30 mm thick rock effect in a small acrylic cube can consume a large percentage of the usable floor. Thin textured skins, narrow bark profiles and shallow pockets often create a stronger habitat because they preserve the air volume, floor area and clear routes the animal needs.