I've been looking for a good non-toxic formula for killing the many sugar ants we get around our house. This is the easiest thing in the world and a great way to get your kids to help. Just give them a spray bottle of this stuff and let them loose on the ants/ant hills. It is completely safe and when you add peppermint oil to the mix, you mess up the ants' pheromone trail. Apparently they hate peppermint! It is safe to use on ornamental plants, but it may cause discoloration. Also, I've heard that if you find an ant hill/nest, you can pour boiling water on it and it will kill them. Another non-toxic idea is to sprinkle Borax (super cheap) anywhere you don't want ants. It will oxidize the ants. Be careful, though, because I don't know what it would do to ornamental plants or your lawn.
Homemade, Non-Toxic Ant Killer/Deterrent Recipe:
In a 16 oz spray bottle, fill half way with water. Add 3 Tbl liquid dishwashing detergent, or an enviromentally friendly liquid soap. Then add 4 tsp. peppermint oil. Shake well and spray!
Talk about easy! The soap kills the ants, the peppermint oil acts as a deterrent. If you don't want to kill the ants, just deter them, then omit the liquid soap and spray wherever you might think they might be coming in the house.