Which ant is known for its painful sting and aggressive nature?

The red imported fire ant is well-known for both its painful sting and aggressive nature. This species is distinguished by its ability to deliver a sting that can cause a burning sensation, which is where it derives part of its name. Additionally, fire ants are characterized by their social behavior, often forming large colonies that defend their nests aggressively when threatened. This aggressiveness, coupled with their potent sting, makes them particularly notable among various ant species.

In contrast, the other choices are not known for a similar combination of painful stings and aggressive behavior. The cornfield ant, pavement ant, and acrobat ant have different behaviors and sting characteristics that do not match the reputation of the red imported fire ant. This makes the red imported fire ant the correct answer to the question regarding which ant is known for its painful sting and aggressive nature.