Looks like building to me too. The best way I've found to separate building from ovy is by looking for the "tail suck". Here's a thread I started last year of one of my females ovulating and what the tail looks like when it happens. http://ball-pythons.net/forums/showt...59#post1278059
I'm sure not EVERY female does this, but every one of mine has
Good luck...... what was she paired with?

Kristin