Aren't nugs native to the deep roads?
Relevant Codex entries. Origins first, Inquisition second.
Origins: http://dragonage.wik...odex_entry:_Nug
The nug is an omnivore common to the Deep Roads, a hairless creature that is almost blind as well as completely docile. It spends most of its time wading in shallow pools as well as mud pits, feeding on small insects, worms, and (in a pinch) limestone and simple metals. Indeed, the digestive system of the nug is legendary, able to make a meal out of almost anything a nug finds on the cavern floors. Nugs reproduce rapidly, spreading into any niche within the Deep Roads they can find, and serve to support a variety of predators such as giant spiders and deepstalkers. So, too, do dwarves make meals out of them... nugs are, in the poorer slum portions of Orzammar, one of the most common sources of meat available. Some dwarves even domesticate the creatures, claiming to find the creature's high-pitched squeaks pleasing.
Inquisition: http://dragonage.wik...g_(Inquisition)
I was sure before the Blight they were a whole lot more rare. Should ask a Warden about that, if killing Archdemons leaves nugs all over. And the poor things don't seem built for anywhere. I mean, they feed on anything, but they blister in the desert and freeze in the snow, and they're easier to track than your own arse. Everything eats them (except me, the hands put me off), yet they thrive. Randy bastards outpace every tooth and claw.
Anyway, my point is, the ones around the farm are so inbred, they're five colors and can't stop peeing. I'm selling them in the capital as "elusive eastern bunny-pigs." What did Father say about idiots with deep pockets?
—Excerpt from the private letters of "Captain" Byrne, lap-nug dealer, produced in evidence after seven claims of Water Terrors and death following bites in the Garden District, 9:36