This is the best way to kill Argentine ants I have found, and I have tried many things over the years. Pesticides that did work were outlawed. Borax in sugar water did not work. All the different type of baits, they were not attracted to them. Amdro Ant Block Bait is the only bait they would take back to their nest. Especially works good around citrus trees, where the ants would “farm” aphids on the leaves. I am in Southern California where the Argentine ant has become a big problem. I also find it works on Black ants that build mounds in the lawn.
Over 9 years I have found the best way to use this bait for me is- I use it as spot treatment. The bottle shows using it as a house perimeter block, spreading it around the whole house. I just sprinkle it lightly along ant trails I see, or where I see ant activity. I could see doing the entire perimeter thing if you have them bad in the house, but I don’t. I have more of a problem with them in the garden now. In the beginning the ants would climb the trees and plants and get in the house. By killing them in the planters, they stay out of the house.
Sprinkle it lightly where you see ants. Do not pile mounds of it, the ants will avoid it and pets could get into it. Sprinkle just enough so you barely see it. Don’t let the bait get wet. Put it out in dry weather or after watering. Don’t worry that the granules look big as an ants head (like my neighbor did), they got strong jaws. After opening the container, the bait can get old and loose effectiveness. I find it lasts about a year before it doesn’t work as well and I have to get a new supply. Be patient! It takes about a week to see results. By being patient and not using a spray that kills just the ants you see and leaves a toxic residue, the nest and queen will be destroyed. Amdro is not cheap, but it works. You can get it at Amazon, all major home improvement centers and Walmart.