Using the wrong enclosure style
Rear Horned Baboons are fossorial, so long periods underground, closed burrow entrances and heavy excavation are normal for Ceratogyrus darlingi. Build the enclosure around that lifestyle instead of using the same shape for every tarantula.
For Ceratogyrus darlingi, adult size is about 12–14 cm (4.75–5.5 in), but enclosure size should still follow the spider's current size. A sling does not benefit from being placed straight into a large adult setup.
Getting moisture wrong
For Rear Horned Baboons, keep the enclosure mostly dry, with surface with a modest moisture gradient below. Provide water and ventilation. The mistake is usually treating the whole enclosure as either permanently wet or permanently dry instead of watching how the substrate actually behaves.
Keep fresh water available to Ceratogyrus darlingi. Persistent condensation, a stale smell or wet substrate that never dries are reasons to reduce water or improve airflow.
Overfeeding or chasing a schedule
Feed Rear Horned Baboons according to size, appetite and abdomen, not because a calendar says food is due. Ceratogyrus darlingi can refuse meals for normal reasons, especially around premoult.
Do not keep adding prey when a Rear Horned Baboon is already very well fed. Remove ignored live feeders and offer food again later.
Disturbing premoult or moulting
When Ceratogyrus darlingi shows premoult signs, remove live prey and leave the spider alone. A closed retreat is not an invitation to open it and check what is happening.
After a moult, wait until a Rear Horned Baboon has hardened and the fangs have darkened before feeding. Larger spiders usually need longer than tiny slings.
Making maintenance too difficult
A good Ceratogyrus darlingi enclosure lets you refill water and remove food remains without dismantling the main retreat. If every job requires moving cork, digging into substrate or working directly over the spider, change the layout.
Handling is not part of routine care for Rear Horned Baboons. Use long tools when useful and have a catch cup ready for rehousing.
Changing too much at once
Once a Rear Horned Baboon has settled, avoid repeatedly rearranging the enclosure for appearance. Stable housing usually matters more to Ceratogyrus darlingi than a constantly changing display.
If something needs correcting, change one clear husbandry problem at a time. That makes it easier to see whether Ceratogyrus darlingi settles, feeds and uses the enclosure normally afterward.