Oh, i have had experience with red ants, leaf-cutter ants, argentine ants, and a dozen more. I have had success using DE (diatomacious earth) against ants coming from the street and over the walls to my garden, and a few nesting as well. This entirely organic and food grade DE is mixed up to be a beverage for humans (not this human) who drink it. I only mention this if you are fussy about what you use to keep your garden healthy.
In addition, i use a spray of soapy water with a few drops of clove and cinnamon oils, not to be used on the plants but to be used on the walls where they enter the garden. After a few years, i feel that i have the problem under control, which doesn't mean there are no ants but does mean there are fewer ants and less problems.
At dirtdoctor.com there are some good recipes for killing ants in the garden, especially killing off the nests, with video instructions that i have found very helpful. You want your ants to know that your garden is hostile territory without having to use harmful chemicals and toxins. It takes some perseverance, but you will eventually have fewer and fewer ants. Ants are smart and they learn not to return to hostile territory. I believe you will find the dirtdoctor very helpful.