Ants can bite, but if you have received an injury from an ant, it's more likely a sting.
Though all ants have the ability to bite, most do not bite as a defensive measure with the exception of the velvety tree ant, which is an aggressive biter. Some ant species have the ability to sting and use this as a defensive measure including the red imported fire ant, the harvester ant, and the native fire ant.
In the southern gulf region of the United States, fire ants sting an estimated 40% of the people that live in infested areas and cause an average of 30 deaths per year.
How Ants Sting
The fire ant colony is vicious and if disturbed will simultaneously send hundreds of ants to attack and simultaneously sting the perpetrator. Each ant grabs the skin with its pincer-like jaws raising it slightly then inserts the venomous stinger. Each ant can sting multiple times. If you live in a fire ant infested area, you should always take care to avoid ant mounds, wear boots, and tuck your pant leg inside your boot.
Humans and Stinging Insects
Amazingly, the average person can withstand ten stings per pound of body weight, but it only takes one sting to give a person allergic to stings an anaphylactic reaction. An anaphylactic reaction is a severe allergic response involving the whole body and can include hives, throat constriction, and plummeting blood pressure. An anaphylactic reaction can result in death.