Fire ant
In the United States, fire ants have no natural predators or competitors. They became an invasive species. Native animals are not adapted to these ants. Fire ants are very aggressive. Their colonies can have many queens unlike many other ant species. Because of this, fire ants have spread very fast. By 1965, fire ant mounds spread on the south eastern coast and as far west as Texas. Today they are found in at least 10 southern states. There is a separate group of fire ants living in California.