So I have Carp modded to be tameable. And I currently have them hanging out in a pond (5 deep) In the middle of my fortress (in the main fountain meeting area... except I haven't built the fountain yet.)
So I'm perusing through my list of critters, searching for the merchants who showed up, but aren't at my depot yet (Their wagons took forever to thread threw the trees as it turned out) When I notice that there are hostile things. I use cage traps extensively, so I figured it was a stray caged goblin.
However... then I noticed that the hostile was a pair of Stray Carp <tamed> This... concerned me.
So I zoomed to them, and sure enough there they are, 2 tamed carp, sittin' in a pool.
Now... it just so happens... that there are ramps to said pool, and dwarves/animals wander through it occasionally...
I have not had an incident where my dwarves have been assaulted by my new pets... but I am quite concerned about this. None of them have ever attacked another dwarf (or anything, for that matter. There was a possible groundhog death they could have caused, but that's it.) But it Says hostile...
There is another carp, who HAS killed 1 or 2 fisherdwarves, but I keep that one separated in a cage untamed elsewhere in the fortress.