Jennifer, I live in Seattle now but originally from Detroit! I found Allthingsplants in November, due to interest in Sempervivums, and boy has that escalated since - fair warning! What part of Mi are you? I still have family in Southfield area
I too have something lifting only some of my semps, I think its birds looking for worms, because we do have lots of Robins here, and it is totally random which ones get bothered...doesn't seem to matter regarding, little ones, or with/without roots etc. I just keep picking off any dead leaves and replanting them!
Cheers