There are no true fire ants in Canada or the northeastern United States. The term "fire ants" refers to a select group of ant species in the genus Solenopsis. S. W. Tabor, in his book Fire Ants (Texas A&M University Press, College Station, 2000), provides distribution maps for the six true fire ant species that occur in the United States. These species are not found in the northern half of the United States or in Canada. There are two other ants called "fire ants" that are completely unrelated to the Solenopsis fire ants. The "little fire ant," Wasmannia auropunctata, is a tropical or semitropical ant species that has been found in greenhouses in Canada. See Featured Creatures: Little Fire Ant. The "European fire ant," Myrmica rubra, was accidentally introduced into North America and has now been found in parts of Maine, Massachusetts, New York, Pennsylvania, New Jersey, Washington D. C., Rhode Island, New Hampshire, Ontario, Québec, New Brunswick, and Nova Scotia. For more information, see Featured Creatures: European Fire Ant. There are other ant species in Canada and the northeastern U.S., and some could possibly sting. However, none are as aggressive as the red and black imported fire ants found in the southern U.S. See also FAQ #4664: Where do imported fire ants occur in the United States? and Geographic Distribution of Fire Ants and What are Fire Ants