How to Kill Ants With Dawn Soap & Water

Ants have many benefits for your lawn and garden. For example, these insects clean up debris, help pollinate plants and improve soil structure and aeration as they dig tunnels. However, ants can also be a nuisance. If you choose to control and kill ants in your landscape, try a soap-based eradication strategy instead of turning to more toxic pesticides.

Scientists are still trying to figure out exactly how soap kills ants. It may affect the insects in two ways:

  • Soap penetrates and disrupts the ant's membrane, killing it.
  • Soap strips ants of their protecting coating, causing them to lose water slowly and die of dehydration.

Insecticide Soap Spray

Insecticidal soaps kills ants on contact and can effectively wipe out any ants that may be swarming on plants, crawling up trees or shrubs, or creating trails on a patio or garden shed. Make your own soap spray at home with Dawn dish detergent or any other liquid dish detergent.

If you're worried about contributing unnecessary chemicals to the garden's soil, consider using a biodegradable, organic dish detergent product.

  1. Pour 1 tablespoon of liquid dish detergent into a plastic, reusable spray bottle.
  2. Add 1 pint of tap water, and mix thoroughly.
  3. Spritz the soapy spray directly on ants, as this only works on direct contact. Coat all exposed surfaces of the affected area. For example, if treating a garden plant, spray the solution on all foliage and stems, including on the underside of foliage.
  4. Rinse off the plant's leaves after two hours, spraying the plant with water from a hose or from a clean spray bottle filled with fresh water.

Soapy Water Drench

Soap sprays only control ants that have left the nest. If that's all you want to do, then soap sprays will suffice. However, if you want to eliminate the ants completely, you must kill the ant nest. A soapy water drench can kill the nest of fire ants and some other common ants. It may take three or four drenches to completely wipe out an ant nest. Watch the nest for resumed ant activity and repeat the drenching if necessary.

  1. Add 3 gallons of water to a plastic bucket. This is the amount of water needed to deeply soak and reach the lowest parts of an ant's underground nest.
  2. Pour 3/4 pints of liquid dish detergent into the bucket, and mix thoroughly.
  3. Pour the soapy solution directly onto the ant nest. Soak the entire nest with all 3 gallons of soapy water.