Because they don't feel secure.. Understand that the snake didn't "come from the wild..." They are captive bred and I would be willing to bet money based on the morph that you purchased it's from a breeder. Breeders use racks and that snake was used to being in something MUCH smaller. When you took possession of the animal you probably tripled if not quadrupled what it was used to and put it in a glass fish tank when it was used to being in something dark and probably much better controlled as far as temperature goes. You said you had a ton of issues with the heating mats as well.. All of this is a recipe for a poor feeding snake... Like Deborah mentioned, they are typically trash cans at that age and will over eat if allowed... Once they are older they become more picky but at 98 grams and dropping you don't have the luxury of a 3 month fast..