Knowing what species of ant is present helps to determine the nesting site, food preference, and the best method of management. In most cases, the most effective, permanent solution is to find and treat the nest; queens must be killed to properly eliminate a colony.
Nonchemical methods
Trying to discourage ants from invading the home can be frustrating. Proper food storage and waste management will reduce the food that often attracts workers indoors. Clean all kitchen surfaces, vacuum daily, and rinse recyclable containers before storage. Ant trails can be temporarily disrupted with a mild solution of vinegar and water. Sticky barriers using commercially available materials, such as Tanglefoot or Stickem, or water moats containing soapy water, can be used to prevent ants from reaching plants or other items. Caulk cracks that ants are using to enter the home.
Outdoors
Many ants enter homes from outside nests as they forage for food. To find their nest, follow the ants. You can encourage foraging by setting out attractive food. Ants usually take regular routes to and from their nest and the food source by establishing a chemical (pheromone) trail. The nest may be found by watching where the ants go; for some ants, such as carpenter ants, this works best at night. If the nest is discovered, it can be treated or removed (in the case of rotted wood).