Jennifer – try the cinnamon – I have a vegetable garden in my front yard and had ants all over. I sprinkled it around every raised bed and around the edges of my house – all ants are gone overnight. It’s wonderful!
Cornflour – works every time for us. Ants eat it but can’t digest it. The cornflour is fine enough to be walked back to the nest. We have a lot of ant problems here in Brisbane, but cornflour saves the day !
Boric acid kills ants, but the high percentage to the bait mix usually kills them immediately. What you want is a lower dose — they take the poisoned bait back to the nest to share with the queen and the others. Commercial baits contain about 10% boric acid, you want about 3%. It seems that kitchen-type ants like either sweets or grease. Get some of the commercial bait and mix it with sugar water or grease (shortening, meat drippings, etc), 1/3 bait, 2/3 sugar water or grease. Boric acid is mildly toxic (mostly as an irritant), so I put the poisoned bait in a small screw-top jar with some holes put in the top, saved for just this purpose, and put the bait in that. It keeps it away from curious cats, and the dog can’t get into it even if they knock it onto the floor. LABEL THE JAR!
I had a problem with these buggers coming in through various cracks and all I did was squirt the green Palmolive dish soap in whatever cracks I have seen them come from, it stops the usage of that route forever.