From the title on down, this has B-movie written all over, and by the standards of the giant-mutated insect genre it doesn't disappoint.
Joan Collins is a crass real estate agent trying to hawk a worthless Florida development to a bunch of suckers in pastel leisurewear, only to have her sales pitch ruined by enlarged ants. Cue a lot of running and screaming, and a strange climax in a town where the queen ant has folks running a giant sugar refinery to keep the troops happy.
The result is still low-grade 1977 schlock, with giant ant effects that would have been below-par in 1957, but it is still watchable on a camp level.