Well, if rats are dead, ur snake doesnt have to hunt or strike, so she willl become way more calm, because he has no need to strike even to eat. I u are goin to come to me with the "it will loose it's instincts" story, forget about it, u will own the snake until it passes away, it needs no feedin or huntin instincts.
Feeding once a month wonth make it starve, but it will be hungry most of the time, so once a week until it is one yrs old would be better...