On top of what everybody said, don't forget to feed the appropriate sized food.
A live Medium would be the max appropriate size to feed a ball python. Beyond that, adult large rats are huge and more aware of danger. They can fight back pretty easily and pack a nasty bite. All reasons why I feed smaller meals more frequently than larger and less often. The younger rats are more oblivious to everything. And even if a small rat bit down on an adult snake, it probably wouldn't do much damage. And weanlings and pups are close to harmless. A rat of equivalent size to an adult mouse is harmless.
And all the 'feeder killed snake!' stories are from people who left their snake unattended for extended periods of time or fed inappropriately sized prey. The rat got hungry and went for the only other thing in the tub. So keeping the feeder well fed and watered is important. If your snake doesn't eat within a designated time(mine is 30 mins), just take the feeder out and save it for the next feeding day.
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