This substance is completely natural and safe for use around humans and pets, but it kills ants and other crawling critters. It's composed of ground up fossil pieces that cut into insects' exoskeletons when they walk over it. Sprinkle diatomaceous earth in corners, under the sink, in windowsills, and anywhere else you often see ants.  Every week or two, vacuum up the diatomaceous earth and replace it with fresh powder. This substance doesn't work as well in humid areas, since it loses its sharpness when it becomes wet. If you have a lot of black ants on your carpeting, cover it in a fine layer of baking soda, let it sit for a few hours, then vacuum it up. You can also apply cornstarch to a surface and vacuum it up immediately before you try to vacuum up the black ants. The added cornstarch in the vacuum will suffocate the animal. Certain natural sprays act as insect repellents. You can easily make your own by adding 10 drops of essential oil to a cup of water, then pouring it into a spray bottle. Spray the mixture all over your house to keep ants away. Here are a few essential oils to try:  Eucalyptus oil (don't use this one if you have a cat) Tea tree oil Lavender Peppermint Lemon Windex You might already have a box in your laundry room. This household substance doubles as a very effective insecticide. Simply sprinkle boric acid in corner and around room perimeters. Ants and other critters will die after crawling over the powder. If you don't have any other repellent on hand, try sprinkling some cinnamon in the room where the ants are gathering. Ants are repelled by the fine powder and strong smell. While sprinkling cinnamon won't kill the ants, it might keep them from coming back.
Use diatomaceous earth. Use baking soda to clean carpets. Try an essential oil spray. Use boric acid. Try cinnamon powder.