Wow, quick response!! Thank you!

Well, I have four buildings--one school, one that they "go indoors" into, and two other smaller ones, with another one being built. Does that mean I should be able to handle a population up to 30?

Also, it seems like I read elsewhere that when they reach their limit, they won't even go indoors--that you'll get a message to the effect that there's not enough housing to be thinking of going indoors, or something.

They are most definitely going indoors. A lot.