Bring every essential down to floor level
An elderly African fat-tailed gecko with stiff joints needs an enclosure where nothing essential requires climbing. Start by walking the gecko's nightly route in your mind: warm hide, moist hide, water, food, cool hide. Every stop on that route should be reachable across a flat floor with an entrance the gecko can walk into without lifting its front legs over a lip.
African fat-tailed geckos are ground dwellers even when young, so this adaptation works with the species rather than against it. The change is one of degree: lower, wider, and nearer. Move the hides closer together so the distance between warmth and moisture is a few body lengths, not the length of the enclosure, on nights when the gecko is moving slowly.
Entrances, dishes, and surfaces stiff joints can manage
Entrances matter more than hide size for an elderly African fat-tailed gecko. Widen doorways where you can, choose hides with a ground-level opening, and add a very shallow ramp of cork bark with a gentle angle only where a small step is unavoidable. Test each entrance by watching the gecko use it at dusk.
Lower the water dish until its rim is almost flush with the floor, or use a shallow lid-style dish the gecko can drink from without climbing in and struggling out. Do the same for the feeding dish if you use one, and offer insects with tongs placed close in front of the gecko rather than scattering them across the enclosure for a chase this older hunter may abandon halfway.
Keep the warm, moist, and cool choices, but compress them
An elderly African fat-tailed gecko still needs the same three choices: a warm hide over gentle floor heat in the high eighties, a cool hide in the mid seventies, and a moist hide that supports shedding. Stiff joints do not remove those needs. They change how far the gecko should have to travel between them.
The moist hide deserves special attention in this species and at this age. African fat-tailed geckos come from drier country than leopard geckos, yet an elderly individual sheds less efficiently, and retained skin around stiff toes is harder for the gecko to pull free.
Feeding position and hunting help for a slower gecko
An elderly African fat-tailed gecko with stiff joints often misses strikes or gives up on fast prey. Feed in the same low, open patch of floor each evening, close to the warm hide the gecko emerges from, so the hunt is a short ambush rather than a patrol.
Watch body condition as you adapt. The fat tail should stay plump, because it is this gecko's reserve, and a thinning tail alongside reduced movement suggests the layout is still costing more energy than the gecko can spare, or that pain rather than stiffness alone is limiting it. That combination, or a gecko that stops emerging at all, is the point to involve a reptile veterinarian rather than rearranging the enclosure again.
Small comforts, checked nightly
An elderly African fat-tailed gecko benefits from a nightly two-minute check built around the new layout. Are the dish rims still low after cleaning, has the moist lining dried out, is the gecko using the widened entrance or avoiding it, and are shed and waste appearing normally?
Photograph the finished layout and keep that photo with the care notes, so anyone cleaning the enclosure rebuilds the low version rather than the old taller one from habit. Logging those nightly checks in KinsLe Care Teams, with each completed task marked by time, keeps the low entrances, tong feeding, and toe checks consistent across everyone caring for this gecko.