Once you nuke the nest (ethically, of course), keep your lawn short and dry. Ants love long grass and damp soil. Mow regularly, and don’t overwater. And fill any holes in the lawn with a mix of topsoil and sand – ants hate unstable ground.
Oh, and check your garden furniture. I once found a nest under a kids’ plastic slide. They get everywhere. If you see small piles near patios, pour boiling water into the cracks, but be careful with concrete.
