Here's a simple homemade ant killer
I wrote a post that might help you - https://chascrazycreations.com/diy-bug-repellents-traps/
I use a product called Terro.
I use dry grits. Just sprinkle it over the mound and let the ants do the rest. Make sure, however, that you use it during dry weather.
Pour boiling water on mound
Sprinkle borax around your home and inside the home around the edges of rooms and at doorways.