One thing I noticed a few days ago, in one of my first tries of Fortress Mode.
At one point, I noticed a grey '.' flickering in my farm room. (I hadn't actually got that deep into the game -- I was using the outside river trick.)
I single stepped until it was showing, and looKed at it. A rat. Seems small monsters can spawn anywhere (since the room's only exits were a locked door and via the floodgate).
I think to myself: "Hmm, this could be harmless or very bad, depending on just what Toady has programmed rats to do. Now what do we do about rats... of course, a cat. But I don't control the cats."
Then I realize that I've left the door set on "closed tightly". I make the door pet-passable...
... and immediately after I unpause, a cat goes to the rat by the most direct route. Shortly thereafter, the grey '.' becomes a superscript 2 (ie: corpse).
Earlier in the same game, a dwarf that I had enabled "Mechanic" preference for, spent many turns in "No Job" despite that there was a lever needing a hookup. (s)he eventually did it, but for awhile I wondered if there was some other skill needed. The task was interrupted by one or more of sleep/eat/drink, and there was another delay before (s)he got back to it.
So the cats seem to be more on-task than the dwarves are...
[ August 24, 2006: Message edited by: Michael ]