Group of red imported fire ants (Solenopsis invicta). This ant species is native to South America but has been accidentally introduced to the United States, and have spread across much of the south. Fire ants are so-called owing to their aggressive behavior and painful sting. When attacking, the ant uses powerful jaws to clamp onto the victim, enabling it to thrust its sting (modified ovipositor) and inject venom. The sting causes a painful rash and blisters in humans. The fire ant is considered a serious economic pest, attacking small animals and destroying seedling crops. They are very difficult to eradicate.