Why Ants Enter Homes
According to Colorado State University Extension entomologist W.S. Cranshaw, ants usually nest outside and only enter a home in search of food or water. Most ants like the same foods that we do: those high in sugar, grease and protein. They will also eat dead insects, which can often be found along windowsills in homes. In addition, ants need water. They will use any source of freestanding water or water found around dripping faucets and leaky pipes.
How Ants Get In
Ants are small creatures and adept climbers. They can use almost any crack or hole to enter a home. Areas around windows and doors are common entry points. They can also enter through cracks in foundations, brickwork or walls. Pipes, wires and branches are often used by ants as a method of climbing from the ground to your home.
Preventing Ants from Entering
To prevent ants from getting into your home, it's important to block any entrances they might find. Ants can squeeze through holes and cracks in the foundation or around windows and doors. Use caulk to seal these entrance points. Also, seal the area around pipes and wires. If you have pets, place food and water dishes in a shallow pan filled with soapy water. The water will provide a moat that protects them from ants.
Getting Rid of Ants
Ants use scouts to hunt down sources of food and water. Once found, the scouts lay pheromone trails that worker ants follow. You can eliminate these trails with soap and water, but that's only a temporary fix. For long-term control, baiting is more effective, providing you have eliminated other sources of food for the ants. Ant baits can be purchased or be made using borax (boric acid) and a food source like sugar, peanut butter, corn syrup or bacon grease. University of Nebraska Extension educator Barb Ogg recommends a mixture of 4 tbsp. peanut butter, 6 tbsp. honey and 3/4 tsp. boric acid. Place the bait on index cards in areas where ants have been seen. Replace bait that has gotten stale or been eaten, and leave it out for at least three to four weeks.