How to Kill Little Outdoor Black Ants with Boric Acid
- 1). Sprinkle boric acid around live anthills. Inspect your yard carefully, coating each hill with a thin layer of acid. The little black ants will carry the acid into the hill, feeding it to the larvae and queen. Boric acid eats through the ants' exoskeleton and invades the nervous system, killing them.
- 2). Line each entryway to your home with boric acid. Ants will stop and pick up small bits of the acid instead of coming inside the house for food. You can also spread boric acid in your basement and along cracks in your foundation to keep ants out.
- 3). Add 1 tbsp. boric acid, 1 tsp. sugar, and 2 tbsp. hot water in a bowl, mixing to combine. Soak a cotton ball in the solution, placing one at the entrance to each anthill. Small black ants are most often sugar ants and die after ingesting the mixture.
- 4). Replace the cotton balls daily until the ants are gone. It can take as long as two weeks for worker ants to carry enough solution back to the nest to kill the queen, so be patient and set out new cotton balls as often as necessary.
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