Personally we have used a product called Terro, available at diy stores in the pest control section, it is a liquid you put on the attached cardboard squares and it draws the ants like crazy, they take if back to their colony and it wipes them out. We even use it outside and place it in their parades across the deck.
Here's a simple homemade ant killer
I wrote a post that might help you - https://chascrazycreations.com/diy-bug-repellents-traps/
My go-to that has even rid a home of carpenter ants that 2 visits from the pest control people could not stop:
Mix 50/50 Borax and table sugar
Place under sinks, along their trails, where they feed.
Kills via dissolving their exoskeleton, poisons the trails and they then feed the dead to the nursery and that kills the entire nest.
Hi Justice: his is what I used for my ant problem, it may work for you, too. Make a mix of 1/2 baking soda and 1/2 powdered sugar. Mix well and put around the spots they are in your garden, or inside your home, it's harmless to people and pets. For outside use, you can put it in a bottle, like a pill bottle or something like that. Cut a hole on the edge of the cap, and lay the bottle on it's side so the ants can come in and get the mix. This way, it stays dry if it should rain. They will take it back to the nest and it should kill them. I'd keep it out there all season if you can. The mix makes a gas and the ants can't pass gas, so it kills them. Anything else that eats it will just taste the baking soda and say "Yuck" and walk off. It won't hurt anything that can pass gas, so it's completely safe. It helps to know what type of ant you are trying to get rid of, too. Try this site, scrolling down to see the different types of ants and how to deal with them. Good luck.