Why is my ball python turning itself upside down and staying that way?

If your snake also stargazes it should be taken to a vet to check for IBD (Inclusion Body Disease), a not so rare but untreatable and rapidly fatal neurological disease.

If your snake is a Spider or a Woma, or at least is part Spider or Woma morph, then it is most likely just being weird like they often are. The term used for this behavior in them is called 'Wobble'.

Another time that can occur is during pregnancy, so if that's a possibility then it's probably that. It isn't exactly something to expect with gravid bp's, but it happens sometimes and isn't a bad thing.

I'm not sure what else it could be, but I've also heard that sometimes bp's just do that...for no reason. After concern and attention and blood tests and the like, nothing is found and it's just odd behavior. Apparently some like to randomly do that or lay partially on their side.