I do agree with most of the points given by the others in regard to housing multiple ball pythons together. I house my balls separately for most of those reasons and have done so since I started keeping snakes. And I have housed two females together just for observation and personal curiosity in the past. I willingly housed them together knowing the risks. They started as hatchlings and were together for almost a year before I ended the study. They were both great eaters. They didn't really roam. It did not benefit the snakes, only myself and it still wasn't easier to house them together. Its actually easier to house them on their own than together.......
As for getting sick even though husbandry is good: Easy answer. Stress lowers the immune system.
Reasons that have also persuaded me not to cohabit ball pythons in addition to what was said previously:
- Combat
- Cannibalism (graphic warning)
http://i149.photobucket.com/albums/s67/Smugg_66/BP.jpg
However, with all that said, cohabitation is safely do-able within certain perimeters and a higher level of keeper experience where you can identify when a snake is sound or distressed. Saying its plain wrong to cohabit is incorrect. Just highly unrecommended for most.
Can it be done? Yes.
Should it be done? Maybe not for newbies.
And in regards to snakes in general, some species can and/or need to be housed together permanently/long term in order to breed.
So there are snakes that shouldn't, could, and have to be cohabited. Depends on the species, keeper, and set up.