Overview

Ants are attracted to the sticky honeydew secreted by aphids, leafhoppers, mealybugs, whiteflies, and scale insects. While not problematic in and of itself, the presence of ants in your garden may indicate and/or exacerbate aphid problems. See Aphids, Hoppers, Mealybugs, Scales and Whiteflies.

Specific recommendations for fruit trees 

To prevent ants from entering the foliage crowns of fruit trees, where they may aggravate aphid problems, use a 4-inch wide strip of polyester fiber matting to snugly surround the trunk, covered by a 4-inch wide strip of household plastic wrap. Smear this with a sticky substance such as Ant-Bar. The barrier will stretch as the tree grows, but once it splits, replace it.

Ants & Peonies

Many gardeners notice ants on peony buds and assume that ants are needed for the delicate blossoms to open, however, that is not the case. Ants are almost always after sweet treats, and in this case, they are after the extrafloral nectaries that are located outside of the flower buds.

Carpenter Ants

There are several species of carpenter ants. They can be black, brown, or red, and workers vary in size from 1/8 to 5/8 inch. Carpenter ants are distinguished by having a waist with one node or pedicel, a thorax with a rounded upper surface, and bent antennae, and if wings are present the back wings are smaller than the front wings. If large numbers are present, it means a nest is inside the house. The parent nest is generally in damp wood, dead branches, or a wood pile close to the house. Successful removal of carpenter ants depends on finding and destroying the parent nest.

Integrated Pest Management Strategies

1. Find the parent nest. The key to controlling carpenter ants is to find and destroy the parent nest. This requires following the ants from the house to the parent nest. Carpenter ants follow scent trails. 

2. Treat the nest. If the parent nest is found it can be sprayed or drenched with an insecticide such as carbaryl (Sevin) or other insecticides specifically labeled as effective against ants. Follow label directions. The use of granules outside is generally less effective than spraying the house foundation and areas leading to the parent nest. Control may best be done by professionals.

3. Prevention. Eliminate all leaks and moisture problems. Repair/replace all damaged, wet wood around doors, windows, and siding close to the ground. Remove all wood close to the house and all tree limbs that overhang or touch the house. Seal around any opening in the foundation, water lines, electrical wires, and vents. Caulk all foundation cracks.

Indoor Ants

Ants live in colonies either outside or in the house. They are among the most successful and common insects. They can be a nuisance when they go marching across your kitchen counter as they follow scent (pheromone) trails they have laid down to food and water sources. What you see in your home are worker ants. These worker ants may live for 4-7 years and collect food to take back to the queen and grub-like larvae in the nest. 

Integrated Pest Management Strategies

If the nest is found outside the home

1. Restrict entry points. Trim vegetation away from contact with the house. Seal as many entry points as possible.

2. Repellants. Plant tansy or mint around the house to deter the ants from entering.

3. Treat the nest. If you can locate the nest, pour boiling water into it.

4. Use an insecticide. Sprinkle diatomaceous earth or granular baits around the perimeter of the house. Read the directions before using any insecticide.

If the nest is indoors

1. Sanitation is key. Do not leave dishes in the sink or food on the counter. Remove ready access to food and moisture. Do not place food items in a trash container until the problem has been solved. Caulk openings where the ants may be entering.

2. Check house plants. If they are in a house plant, remove it, preferably outside, and flood it several times with water, or better yet, remove the infested soil and repot in fresh soil. Pitch the plant if that is an option for you.

3. Repellants. Some homeowners report success with repellants. Sprinkle cinnamon, black or cayenne pepper, cloves, bay leaf, mint oil, or mint gum unchewed near the trail. Placing a white chalk line across the trail may keep the ants from crossing. Spray a mixture of 1 cup of white vinegar and 1 cup of water on the countertop.

4. Use baits. These are probably your best option. Your local hardware store will have commercially prepared baits. Solid bait traps work best in late winter and early spring when the workers bring this solid food back to feed the larvae. Adult ants cannot digest solid food. Or you can mix 1 cup warm water with ½ cup sugar and 2 Tbl. boric acid [20 Mule Team Borax]. Put this in bottle caps near their trail. Do not make it too strong. You want the ants to carry this back to the nest to feed to the colony. This may take 3 weeks to be effective. Keep baits away from children and pets.