She bit her tail again this morning and has spent the last six hours wrapped around one of the fake plants in her enclosure. She noses the ground and her coils like she's looking for whatever she thinks she caught, and just now she even decided to bite her actually body after nosing it for a little. She's never had a food drive anywhere close to this before, it feels like it came out of nowhere.
(And now as I'm writing this post, she got so erratic and excited by the vibrations from the garage door opening, which is not a response she normally has)
The probiotics are a good call, I tried adding them to her water a while ago, but it didn't seem very effective so I stopped. I'll try putting them directly on her food. I am also planning to change her to paper towel and clean everything in there, just in case something smells like mouse. I'll email my vet as well, but I'm just not sure what they can really do about it besides another fecal and blood panel.
It is a little disappointing to be dealing with another weird issue, especially one with no clear cause. Ultimately though, I just want to give her a good life. She really is such a nice snake and pet otherwise.