Since I moved out a week ago, I've been letting DF run on its own while I sleep and go to class, pausing only for strange moods and trade caravans (or perhaps I should say THE trade caravan, since there are no humans or elves in this world) and auto-saving every season. This has let me progress much faster than I have before, but it's had some drawbacks. Sometimes the strange mood or trade caravan will come not too long after I leave or go to sleep, leaving my computer doing nothing for hours. Then there are times like this morning where the game crashes and I lose an entire night/day worth of progress; specifically this morning I lost an in-game month, which was about the time it took my miners to channel out another level. It seems, though, to have been a blessing in disguise, since this morning's strange mood required shells and I haven't had any of those in years. Hopefully, I will never see any strange moods that require shells ever again, but maybe I should create a pond outside to generate pond turtles just in case I don't want my miners to get sick in the sun.
You know, maybe one or more of my new cavern creatures should have shells; who wouldn't love to have a herd of hippo-turtles that they could breed and keep around not only for meat but as an emergency shell supply too?