First year. 17 citizens. I'm on a *very* mineral rich site, plenty of natural gold, iron ore, galena, and lignite. It took me awhile to reach the good stuff, so I ended up trading a bunch of near-worthless mudstone trinkets to the trade caravan. I get a 'some migrants have arrived' message.
I watch them come.
... and come...
... and come...
42 migrants. For a fort with 14 people.
The migrant wave nearly quadrupled my population. I'm freaking out because I'm nowhere near ready for this many, I've got 25 bedrooms, a dining room that seats 15, winter's about to hit and I'm not sure if my booze and food stocks will hold up because I had my farmers doing hauling once I figured I had enough to last me for a year with my current population. Plus, only three of them have any useful skills. The rest are farmers (who have maybe a third the skill of my existing farmers), beekeepers, fishery workers, and TWENTY CHILDREN.
What the hell happened? There's no way the caravan sent them here, last time the trade caravan was here I hadn't hit the Native Gold yet - I sold maybe 3k dorfbucks in mudstone crafts. Do migrants just somehow 'know' that I stopped using mudstone and started putting Native Gold cabinets in everybody's room? Don't get me wrong, I love the extra manpower (even if most of it is only good for hauling at the moment), but this is way more than I'm prepared to handle right now!