I have 2 Cherry head red foot tortoises, Once a month I give them live mealworms. I used to have a mealworm farm for my Sugar gliders. Anyway, I learned that if the tortoises don't eat all the mealworms, the worms go down into the substrate and turn into the mealworm beetles. I was feeding my tortoises last night and had an infestation of beetles, ALL OVER. I changed out eh coco substrate and now all is back to normal, It was so creepy. I don't know how long this was going on, but i am glad I discovered it. Just to let all know that this can happen.