There are lots of questions circulating around the reptile and gecko forum that why leopard gecko eat substrate. This is very troublesome for lots of hobbyist as they often prefer to have more natural look for their reptile vivarium. In my opinion, this is our fault! Normally gecko hobbyist did not pay enough attention on the food supplement. In order to balance and gain enough of the food supplements, this animal tends to eat the substrate. I suppose if you are the kind of hobbyists that prefer the natural look of the vivarium and do not want to risk your pet’s life, it’s necessary to provide the gecko with a dish of calcium powder. It should be alright if you provide sufficient and appropriate reptile food supplement to your gecko.
I suppose the time when your gecko is eating the substrate when they’re hunting. However, please don’t forget to monitor the leopard gecko closely to make sure that everything is alright.