Building vs. Ovulation

[brettfong]

What exactly do you look for to find ovulation? And can you describe what the "building" part is. Also do these apply to all snakes or just BPs?
Just new to the breeding side of information.

Building is just the female developing follicles. She'll start to look heavier in the tail end of her body. Ovulation when these follicles are fertilized and she will swell up in one portion of the body (you can see in my pics above). Here's a site with some good info and pictures. http://ballpython.ca/gallery/breeding/

Not sure about other snakes though!