It might not be the ants. Is your grass dying? If so, how is it? In spots? in patches? You said you planted... meaning you put grass seed down? or sod? If you planted by seed, did you cover it with straw (or other covering), how much have you been watering it? In the first few weeks of a newly seeded lawn, watering is essential. The best time to plant a new lawn is in the fall, when the blades of grass do not have to compete with weeds, or the summer heat, so if its been very hot in your area that could be the problem too.

The ants bringing up sand are not hurting a thing....keep watrering....2 or 3 times a day in summer in sandy soil.....and when the grass gets a start and the weather cools down, spray an insecticide on the lawn.
your main challange is hot weather.....has the seed germinated?
Linda C

Use a molasses spray to blanket the infected area and the ants will go away.