6 Month Old Ball Python still acting hungry after two small mice?

[Bogertophis]

Well, he had never done that before and I am still new to this. Will it be harmful that I fed him two?

No...snakes in the wild don't follow these charts, & most get along fine as far as we can possibly know. It's just that with pet snakes we want what is best for them, from our experience. We don't recommend over-feeding, nor under-feeding, and this is just to give you a guideline to go by. It's actually more like what would happen in nature: snakes eat whatever they can find & catch: sometimes it's bigger than is best, other times it's too small & they just have to get along the best they can. (A meal that is REALLY too big can be harmful, by either causing internal damage or aspiration & death from a failed regurgitation, so obviously you never want to push the limits just to "see" what a snake can swallow.) Snakes in the wild also don't stick with a feeding schedule, & are more likely to be under-fed than over-fed because food is scarce & life in the wild is a lot harder.