Sort of? They generally live in their own area's but they tend to think a lot of land that people live on is also their area (and I mean, they're probably right?), and all High Dragons are females so whenever they don't breed your best bet is to leave them the hell alone unless it can't be avoided (or you find them in a random mine they shouldn't really be in) but when they want to breed they draw drakelings in and start decimating the countryside because they suddenly need to feed their kids and their like dozens of men folk so you gotta eliminate them. Ironically when the Chantry was all 'we're going to call this the Dragon Age' they all must have heard that because they've been showing up a lot. Usually the High Dragons only breed like every hundred years and you get maybe one of those, but it's been different these last few years.