I do like Luke's line of thinking, though: I need a danged ultrasound!
You and me both! I've actually been working on picking one up this summer myself. I've got a few females that haven't produced for me in a few years that I need to pay more attention to in that area.
If I had a female lay slugs for a second year in a row, that's all I'd try her, unless she was one of my favorite morphs; and she was paired with a different male the 2nd time than the 1st.