Feeding & Water
1 frozen/thawed mouse or rat every 7-14 days.
Dechlorinate tap water and replace often.
Ball pythons are notorious for being some of the pickiest and most difficult "beginner" snakes to feed. Sometimes, a ball python will eat its meal every time, no problem, for years. Then suddenly, refuse to eat for days, weeks, or months. (Some reports mention their ball python being off feed for over a year.)
This often causes panic in new keepers, because obviously, animals need food! We'll get to why ball pythons go off feed, and what to do about it farther down, but let's get started on the general "rules" of feeding.
When deciding what size prey to feed your ball python, try and find something similar to the girth of your snake's thickest body part. For example, measure around the snake's belly, and do the same with frozen rodents, or compare the size to the measurement of rodents for sale online.
If you feed this size prey, ball python a couple years or younger generally does great with 1 mouse or rat per week. Adult ball pythons don't always need as much food compared to how much they were eating as younger snakes, since their growth rates slow down. Anywhere between once every 7 to 14 days works for adults. If feeding smaller sized prey, you can feed more frequently, or more than 1 rodent in one sitting. Keeping track of how your snake looks weight-wise is the easiest way to gauge how much to feed. On the chubby side? Maybe feed a little less often! Looking too thin? Up the meals in frequency! This is not an exact science.
Some people say you should avoid feeding multiple rodents at once. I did a video on my opinions of this here.
HOW TO FEED
Simply hold the mouse with snake tongs to avoid your hands being mistaken for food and gently wiggle the mouse around the head of your snake until it strikes and grabs the rodent. Avoid sudden jerks with the food away after it's bitten. Pulling the mouse too hard could result in your snake losing a tooth, although this is rare. Handling your snake after feeding may result in a regurgitated meal, which is not only a waste of a mouse, but very demanding on your snake's body to vomit up.
Should you feed your snakes outside of their enclosure, like in a separate tub? I highly don't suggest it. "Cage aggression" is a term often thrown around that describes a snake who connects hands around its enclosure with food, therefor increasing the chances of being bitten. However, I have yet to see any proof of this being true.
How long you should wait after feeding depends on both who you ask, and on the snake itself. For example, I could handle some of my snakes a couple hours after feeding and they wouldn't care (although I still avoid it whenever possible) while others need a few days to digest. I generally suggest waiting 24 hours before handling, however, some people will tell you 48 to 72 hours. The more you get to know your snake, the better you'll be able to gauge this. A good way to ensure you don't stress the snake out is by feeding the him/her before you go to bed, allowing the snake to digest overnight.
MICE OR RATS?
Ball pythons get larger than other popular snakes, like corn snakes - which can simply eat mice their entire life. Ball pythons, however, are going to want larger prey items, meaning you'll eventually need to switch to rats. Sometimes, ball pythons are so picky, that they don't want to give up mice for the unfamiliar flavor of rats. Because of this, many keepers start their snakes on rats from the very start. The only downsides of doing so are that rats sometimes have less availability than mice, and they're usually a little more expensive.