Something that can kill ants? (pls. something that's not popular)?

Something that can kill ants. Not toxic and better if you can put in on the skin. Not a lotion or any brand of insect repellent but something that's like found on leaves or flowers or fruits or anything. Please give the scientific name if you know. For a project. Gotta invent something. if you don't know anything just give something unpopular that's invented. :D