What the substrate needs to do
Use a clean soil-style substrate for Davus pentaloris that can hold its shape without becoming hard, dusty or permanently waterlogged.
For Davus pentaloris, the substrate in a Guatemalan Tiger Rump enclosure should support normal movement and retreat building. Heavy decor must not be able to collapse if the spider digs underneath it.
Depth
Guatemalan Tiger Rumps are terrestrial, so give Davus pentaloris enough substrate for normal digging while also keeping the fall distance from the lid low. A stable ground-level hide should sit securely on or in the substrate.
Match substrate depth to the current size of Davus pentaloris. Small slings and fossorial individuals often use proportionally more depth than a large settled terrestrial adult.
Moisture
For Guatemalan Tiger Rumps, keep a water dish available and maintain a modest moisture gradient; avoid saturated substrate. Add water in a controlled area and judge how the enclosure changes over several days instead of trying to keep every centimetre equally wet.
Substrate moisture for Davus pentaloris should work together with ventilation. Persistent condensation, a stale smell or widespread mould usually means the setup is staying too wet.
Compaction and stability
Press the lower substrate layers firmly enough that a retreat or burrow for Davus pentaloris does not collapse immediately. The upper surface can remain looser where appropriate.
For Davus pentaloris, keep rocks, heavy cork and ornaments in a Guatemalan Tiger Rump enclosure low and secure so excavation cannot undermine them.
When substrate needs replacing
Spot-clean waste and prey remains from the Davus pentaloris enclosure. Normal digging, webbing or rearrangement by the spider is not a reason to replace clean substrate.
For Davus pentaloris, replace all substrate for a Guatemalan Tiger Rump only when it is fouled, contaminated, persistently mouldy or no longer structurally usable.