Two species of fire ants are found in Florida. Most notorious is Solenopsis invicta Buren, the red imported fire ant (RIFA), followed by the much less common Solenopsis geminata (Fabricius), the tropical or native fire ant.
Leaf curl is a plant disease characterized by curling of leaves, and caused by a fungus, genus Taphrina, or virus, especially genus Begomovirus of the family Geminiviridae.
Tomato leaf curl can be caused by a variety of things of which bugs (usually aphids) are only one. Look at the underside of the leaves that are curling. If you don't see aphids, it will either be normal for the leaves to curl or you have a fungus/viral problem.