The only effective way to kill ants on a lawn is to use traditional pesticides, which usually come in liquid sprays or granules. Pesticides containing either bifenrin or cylufrin are both known to be quite effective at killing ants.Continue Reading
If the ants are concentrated in certain smaller areas, these can normally be taken care of with a spot treatment of a general insecticide. However, it is usually necessary to treat the entire lawn with pesticide for larger scale ant problems, which should likely kill all other insects as well. The insecticide should be applied either early in the morning or late in the evening, as this is when the ants are most active and most likely to bring the chemicals back to their nest. It is also important to mow the lawn immediately before applying.
Some ant species are notoriously hard to get rid of and sometimes even pesticide doesn't solve the problem. Fire ants are one of the harder species to control and there are even insecticide granules designed specifically for these ants. These products have been designed to look like food to the fire ants, which then pick up the granules, take them back to the nest and spread the poison.
There have been studies that have shown that some species of ants aren't killed by the pesticides, but instead driven away to somewhere nearby.Learn more about Pest Control