Field Ant


Actual Size: 4 to 8 mm

Characteristics: Large; black, brown, or yellowish to bicolored red and black 

Legs: 6

Antennae: Yes

Habitat: Favors outdoor nests in decayed logs or soil. Nests located in lawns, gardens, fields, and foundations of homes and buildings


  • Feeds exclusively on outdoor food resources.
  • Sometimes field ant mounds are mistaken for fire ant activity.
  • Rarely found indoors, but common around homes and other buildings. 

Field Ants in Wisconsin

Field ants get their name due to their preference for nesting out in the open. Nests can be found throughout Wisconsin in lawns, gardens, fields, and parks. Field ants build large mounds in open areas reaching sizes of three to four feet wide and up to two feet tall. Rarely found indoors, field ants are common around structures and homes. Most species of field ants cause issues around homes or buildings when they nest near concrete sidewalks and masonry walls.

Field Ant Habitat

Nesting in soil or decayed logs, field ants build mounds. Sometimes people mistake field ant mounds for fire ant activity. Nests are constructed from small twigs, grass stems, leaves, or pine needles. Field ant nests are found around shrubs, sidewalks, fences, and the foundations of structures. Unlike most ant pest species, field ants do not come indoors for food. They feed exclusively on outdoor food resources, such as live and dead insects and the honeydew produced by aphids.

Field Ant Behaviors, Threats, or Dangers

Field ants do not sting, however, they will bite if disturbed. If nests are destroyed or stood upon, ants may aggressively swarm out of the nest and bite the intruder. Their bite is painful, with some species spraying formic acid into the wound, which will sting. While painful at first, the sensation will subside, and their bites do not have any long-term consequences. The large mounds that field ants build can ruin the look of lawns, making lawn mowing difficult, and interfering with the growth of garden plants and woody ornamentals. If a field ant infestation is suspected, it is best to consult a professional ant exterminator