I also feed according to eyeing up the sizes. Like today was feeding day for me and one of my female albino's who has been eating 2 mice at one sitting I fed her a baby gerbil today. It seemed to look a bit on the larger side in the box but you have to remember too that you have to try and picture the prey arms and legs extended and no air in them they seem to shrink a bit when they have expired. So she was fine with that and she doesn't have an overly large "knot" in her stomach area. She looks pretty even. Just my 2 cents.