How many ball pythons can you have in one aquarium? As many as you want. How many should you have? One.

Snakes really should not be housed together. Ball pythons especially.

They are one of the most sensitive species in the pet trade. They are VERY easy to stress. It can be something as simple as the humidity or heat being off by just a tad, too much traffic going by the cage, etc. When such occurs they either start showing signs of distress (health issues) or they go on a hunger strike.

Now add a second snake to the equation. Need I say more?

corn snake
king snake
multiple ball pythons (all in separate enclosures)

For a ball python one. However there are snakes that can be housed in "groups" per say. Like the African House Snake, Rosy/Rubber Boas, and Garter Snakes. I know its never recommend to do this because of aggressive cage mates during feeding and breeding season, plus the chance of spreading a sickness to the other snakes but nevertheless you can house them together with a chance of not having a complete massacre in your cage.

My male and female have lived together in a huge 150 gal tank for almost 2 years and it's in the main hallway of my apartment. Some pythons are not as sensitive I guess. It obviously doesn't work for some people, but it's working for me.

Here they are.. http://www.youtube.com/watch?v=tcR4A8aR8