Non toxic fire ant killer

[Debd]

I have several fire ant mounds around the barn area and would like to find the best non toxic treatment. This is an area where the horses graze. I plan on using diatomaceous earth, but have heard this doesn't always work. I've also been reading about the product "Anti Fuego", which is a mixture of orange oil, molasses and compost tea. Has anyone used these and had any success. I've seen Amdro mentioned, but I thought that would be harmful to the minis.

Thanks in advance for any advice you can provide.

Deb