So if you have a healthy snake at 450g to 500g you are looking at the white rat 5 from the left or 4 from the right.(at the least)
The day I brought home my little Queen Bee (Charlotte) she devoured a live rat similar to the one third from the left...She was all of 7 inches long and was slightly heavier than a pencil. They were feeding he live and I wanted her to eat but she has since been switched to F/T. If you feed live (or stunned) remember that the rodent if fluffy and it is not actually as big as you think! (dip it in hot water and you'll see...but not alive!)
Now, there are protocols for starting and switching a hatchlings which we will not get into as that is not the focus of this thread. Live v F/T which again is not the focus of this thread.
Give you snake what it needs, in the quantity it needs and if you are thinking to yourself: "There is no way that rat will go in that snake"....try....you are probably wrong.
Have fun....welcome...if you are not sure...ask.