Are these black ants? They are the only ones I have experience with.
I use food grade DE (diatomaceous earth). Its powder like. Technically is fossilized white algae or plankton or something but its microscopic and slices up bugs while being organic and completely safe for people and "non bug" pets like a tortoise
I use it every summer. Sprinkle it on the ant hill or along the ant trails and they leave.
Bought a 50lb bag of it for like $18 at a local feed store.
I use boiling water with a little white vinegar to get rid of fire ants. I may take more than one application but its safe and pretty effective. It will leave a brown patch if there is grass but it should come back.
My lawn seems to be one large black ant nest at times. I ignore them... there is no way I could get rid of them. They cause nuisance to me when they get in the house; that is all.
Please make sure to get food grade DE and not the pool type....I am sure you already know that but every time I see DE in a conversation I am compelled to repeat that..... Apology for my OCD ....