Just saw a huge swarm of ants on the balcony on the
upper rafters. Sprayed an entire can of raid, but where
do these red and swarms come from?

Every 100th or 500th ant was big, with wings. Maybe thirty
or forty out of thousands had wings. The rest are two or
three millimeter red ants.

Any idea why the swarm?
I've lived here for five years and have never seen that.