So one day as I was perusing the Prim Tattoo in search of semi-gainful employment, I stumbled over a nest of roaches (rather dreadfully maintained establishment, if I do say so myself). What piqued my interest was that these cockroaches can apparently walk on air. I was under the impression that such flying beasties only existed farther south.
I suppose I was wrong.
Did a cursory check, couldn't find any related topics. I caused a vermin scare ("many large roaches have been disturbed") while walking along the one-tile wide catwalk. The roaches spawned in mid-air, and, now that I checked, inside the wall as well. I'm pretty sure the roaches in dwarf fortress can't fly, but I
know they can't walk through walls.
I'm guessing the vermin scare event just isn't checking to see what it's getting the little buggers into.
EDIT: Added shot of bugs in the wall. Sorry about the large image size, didn't take the time to shrink'em.
EDIT2: Since I'm here, I might as well put in a mention for another oddity I found. First of all, booze seems to be considered food as far as looting is concerned, so it's not uncommon to find puddles of alcoholic beverages littering the floor of a cavern. They're perfectly good to drink, too. All you need to do is pick it up and brush the dust off.
Well, that's one part of the fun stuff. The other part is that I apparently picked up some booze when I had a free grasp. I just now noticed a peculiar death message after killing a naked mole dog, and after a little investigation I found that my character was beating people to death with some longland beer.
As fun as a beer bash can be, I don't think this is really intended behaviour. Pity I can't put the thing in my waterskin...
EDIT3: Okay, I can't put beer or wine into my waterskin. But I
can put an earring in it. That makes sense.