My saharan uromastyx's age is unknown to me, probably 7 inches. I've had him about 8 months. Recently, he doesn't seem to be dying but is sleeping a ton in his cave on the cooler side of his 40 gallon breeder (36x18x16). When I lift up his cave, I find his body temperature cold, and he's asleep. I keep a 150watt bulb over his tank and an 18" UVB Repti bulb and fixture over that end too. His substrate is washed playsand, I used to use millet seed but didn't like it, he kept digging in it but just kicks all over the place. I leave no water in his tank. I feed him tons of mixed greens, flower petals, lentils and some seeds. Lately he's not eaten, he just wants to sleep in his cave where I find him with a cold body every day. I try to place him on the hot end on his basking slate or rocks, but he will stay maybe 5 minutes, then he proceeds to walk around a few minutes before finding his way back into his cave on the cool end. I am no expert but I do not believe he's dying or sick, he walks, acts fine for the 10 minutes a day I see him. Sorry for the long post, but I am wondering if he or SHE, brumating and if so am I disrupting that by removing him from his cave and to the hot side at least once daily?