If you change its tub size because its not eating, put it in a smaller tub. They feel more secure in a smaller tub and will eat more readily than if you put it in a bigger tub. I'll pull 1500 gram females out of breeder tubs and toss them in a 12qt and they'll start eating most of the time. They fill up the WHOLE tub, but if they weren't happy they wouldn't be eating!