They started in Houston Texas and they are spreading rapidly. They don't sting like fire ants, but they may be worse because: a) they form super-colonies that contain billions of ants, and b) they love electrical equipment. Once thousands of ants get inside a computer, an air conditioner or a control box, they short things out.
They are called crazy raspberry ants:
Destructive ants marching on San Antonio
"Where you'll have 200,000 ants in a big fire ant mound, you'll have billions of crazy ants in one area, in that one group. They form a carpet of ants over acres that is several inches thick."
"It's a potential ecological disaster, displacing everything in front of it, other insects. Some people think getting rid of insects is good but it's not good for the environment. Insects play a vital role. When you destroy insects, you destroy the food for birds and other animals that depend on these insect populations. It could affect our food supply, reducing the crop yield by 30 to 40 percent."
More info:
Crazy ants that infested a computer mouse:
See also: Why the "crazy rasberry" ant infests electronic devices
