Why Do I Have Ants in My House?

By Chris Williams on July 11, 2016.

When ants invade a home, it is almost always a case of “If you provide it, they will come.” We’re talking about food. Ants randomly forage out from their colonies, looking for available food sources. If that food happens to be in your house, it’s chow time!

In most cases, ants first get into your home accidentally when a single exploring ant discovers an opening – through a window, under a door, or through a crack in the foundation. That ant wanders around in this new indoor space and if it discovers food, it soon returns and spreads the word to the rest of the colony. Food for ants can be spilled crumbs on the kitchen floor, chicken bones in the garbage can, pet food in a dog bowl, empty soda cans in the recycling bin, dead insects in the attic, even grass seed in the garage. Many different things in your home can spark an ant’s appetite.

You Provide the Dinner, They Provide the Guests

That scout ant returns to its outdoor colony and recruits other ants to this great new food source. As other ants make their way to your house, they put down a scent trail, leaving pheromones for other ants to follow. Pretty soon there is a regular ant highway following this chemical trail between your house and the colony (see Ant Highways Are Much Like People Highways). Ants collect bits of the food and take it back to feed others in the nest.

If they really like your place, ants might establish a secondary nest site (or two) in your home, shortening the distance that they need to travel to reach food. If the ants happen to be carpenter ants, they’ll hope to find some damp or water-damaged wood to excavate for a nest site. Other ants can end up nesting in wall or ceiling voids, and depending on the ant, in other obscure places like behind baseboards or window moldings, inside curtain rods, in stacks of newspaper, and in potted plants.

There is one plus side to having ants foraging in your house. Actively foraging ants are easier to bait and control. We put out small amounts of food impregnated with insecticides along trails that the ants are following. The ants discover these toxic baits and carry them back to the colony, eventually killing the colony and eliminating your ant problem.

How Do I Get Rid of the Ants in My House?

(1) Clean up – remove any available food and keep kitchen surfaces clean.

(2) Seal up – caulk or seal or screen any openings that ants are using to get inside

(3) Call up – a professional exterminator will inspect, looking for the source of your ants and will design a control program to get rid of them. That program might involve baiting the ants, treating the nest site, and placing an insecticide barrier around the foundation of your home.

For more on invading ants, see these Colonial blogs:

Photo Credit : “Ants eating fruit” by Zainichi Gaikokujin until nobody found original 😀 (Kidding, don’t mind) – Own work. Licensed under CC BY 3.0 via Wikimedia Commons.



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