A couple weeks ago I noticed a small hard bump on the very top on my ball python's back. It just looks as though her back is raised slightly & it's no more than half an inch long. I took her to the pet store & the guy said he didn't know what it was but it didn't feel like an infection because it was so solid (no sign of fluid/bacteria). There is no broken skin or anything wrong with her scales & she doesn't get bothered at all when you touch it or put pressue on it.

Anyone know what this might be?