There's very little actual damage caused by cornfield ants, especially when compared to the active destruction caused by carpenter ants. The nesting of cornfield ants sometimes causes small "craters" in the lawn, garden, or planter boxes. Brick paver patios or driveways can sag if ants colonize below and excavate soil to create a nest. And occasionally, cornfield ants can exaggerate the damage to wood that has already been infiltrated by carpenter ants. They do not, however, eat wood, but instead only inhabit galleries already carved by other insects.