Effects. Lawn damage caused by ants infestations depends on the ant type and level of infestation. Ant nests or underground tunneling result in damage to the nest area and surrounding grass or plants, and anthills or mounds make the lawn uneven and mowing hard.n ant infestation in a lawn is frustrating and ruins the appearance of the grass. Ants damage lawns in both small and large numbers, and simple tasks such as mowing become difficult as nesting mounds can sometimes damage metal mower blades.