So do they recognize the Bermuda Grass is from Africa, and is that why they are happy with it as bedding? Reminds them of their home origin? Cool, i am doing something right for them.

I adopted a sulcata 5 years ago that was fed grocery store greens only. It took a lot of patience but I eventually got him onto hay. I chopped the green, dry hay along with grass from the yard into 1/4" long pieces and would soak it in warm water for a few minutes before I drained it and put it on top of the dandelion greens, etc. When they are young it is difficult for them to bite off large pieces of dry hay. Think about it... the leaves they eat are attached to a plant in the wild, not loose on the cage floor or in a bowl. I buy calcium carbonate powder from a vitamin store online and sprinkle that on his food-lots cheaper than the pet stores and no potential vit D overload. Of course for vitamin D3 my guy is housed outside since he is now large enough. I also sprinkle a multivitamin on his food once a week. His main diet is the grass (different types) I grow in my yard supplemented with flowers, weeds and occasional shredded carrots etc. Better to give them vitamin precursors when possible to limit vitamin overdosing-especially of the fat soluble vitamins. Look up Dr Sue Donahue's info on sulcatas. She has even written some articles on the microbial gut flora of sulcatas that helps you to understand why fiber length is important. Are they warm enough? Do they have enough visible light as well as the UV source? I would take mine outside in the sunshine for 15 minutes every day while he was little. Good luck.

You should grow several types of grass. You can order pasture grass seed mixes online. Try High Country gardens or some native plant nurseries. I saw somewhere recently supposedly selling grass seed native to their habitat in Africa. I'll have to find it again. Of course it is not usually advisable to import foreign plant species. I have planted several different types of native California grasses along with my lawn of St Augustine.