> Rumor has it that the developers here hauled away the topsoil and sold
> it!

That is common.  The lack of soil makes it easier to build on when it
rains (no mud), plus they make a few extra bucks.  Now, you have to turn
around and buy someone else's topsoil  :)

> Since we've been here, we've done some things to improve the soil
> (bags of stuff)

What kind of stuff?  Most "organic copmost" is actually industrial waste.
The "organic" part they are referring to is that it contains carbon, not
that it is natural.

> and I've been digging under almost all of the organic
> food wastes for 7 yrs. just under the surface, so they'll decompose.  Is
> that a bad idea (fostering ants)?

Well, it is a method that lots of people like.  Similar to the Ruth Stout
method (compost it in the garden instead of in a bin).  But I would rather
compost it in a pile or bin.