My lawn which is very thin (newly seeded) is covered in sand. The ants appear to building nests and are digging out the sand. This is the first time I have seen this problem. The ants are very tiny and I see them mass together on my patio then march back to the lawn if water spills on the patio. In the past I have used “ants be gone on my patio” with success.
We also have a very large flower and shrub/tree bed and that also is covered in sand.
Please advise what solution I should use.
The ants in your lawn and garden seem to be enjoying your sandy soil to make their nests. Adding plenty of organic matter such as compost to improve your soil texture and provide nutrients for your plants is important every year. Your newly seeded lawn could benefit from a top-dressing of organic matter and reseeding this fall to help it get established. For control of ants outdoors, the Ontario Ministry of Environment has approved the use of borax as well as diatomaceous earth for the control of these insects in the garden, so those are methods to try. Below are links to Gardening Guides on improving your soil and organic pest control for more details. There is also an article published in Fine Gardening that explains how helpful ants can be and may change your mind about ants in the garden: