Ants in the Home

Robert Bishop 
Frederick County Master Gardener Program

Most of the ants found in the home are a harmless nuisance. Two species, the large black carpenter ant and the tiny Pharaoh ant can be more of a problem. Carpenter ants can cause structural damage to the house. Pharaoh ants are persistent and very difficult to control but do not cause damage.

Ants live in very social groups (like bees, hornets & wasps) called colonies. Worker ants do not have wings, but male and female ants develop wings at certain times of the years to enable them to mate. Winged ants have elbowed antennae, a narrow waist, and two sets of wings each with a different length. Termites look different than winged ants in all three characteristics. Termites have straight antennae, thick waist, and also two sets of wings, but both sets are the same length.

Ant mating occurs in the air in a large group of winged males and females called a swarm. After mating the males die and the females finds a place to lay their eggs and remove their wings. Then the female becomes the Queen of the colony and feeds the young larvae as they hatch and become the workers. The worker ants leave the nest daily and forage for food. They feed themselves and the Queen so she can continue to lay more eggs. Worker ants live between 6 weeks and 2 years, Queens can live up to 20 years. As the colony grows some larvae develop into winged males and females and leave to mate and start new colonies.

Ants are attracted into homes from their outdoor nests by food odors as they forage. To discourage them store food properly in tight containers. Rinse cans, jars, and other food containers well before placing them in the trash or recycling bin. Ants like sweets and grease. Keep the kitchen as clean as possible especially the sides of the oven, floor under the refrigerator and oven, and around the trash can. Look for routes the ants follow from their outdoor nest to food source in the house. Try to seal off access to the house with caulk, weather stripping, or another method.

Trap ants in the home using poison bait type traps. These are available in most hardware stores. The ants will be attracted to the traps and you will avoid spraying insecticides in the home. Traps take time to work, be patient. If you have a large amount of ants you will need more traps. Larger size ants like carpenter ants also require using more traps for effective control. The Pharaoh ant is tiny and must be controlled using traps specifically made for them, (Maxforce is one brand).

If the ant problem is not controlled after about one week using poison bait traps try to locate the nest. It may be inside the house. Locating the nest is a little difficult but can be done in time with some effort. Common locations in the house are under basement floors, behind baseboards and walls, near leaky pipes, piled newspaper, and any rotted wood. Spot treat the foraging trails and nest with a labeled insecticide formulated for indoor use or contact a professional exterminator.

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