Product Education   |   March 27, 2024

You can’t control what you can’t see: managing hard-to-find ant colonies

What is the definition of “ant-sanity”? Performing the same ant control service every time and expecting different results. Ants are one of the most challenging pests to control in or around structures, if not the most challenging. The ants we see, known as foraging workers, make up only a small percentage of the total ants in a colony (typically between 2-10%). For this reason, only managing foraging workers but expecting full colony control can lead to feelings of “ant-sanity” as populations rebound, leading to costly retreatments


Finding the nest and getting products to it is essential for a successful ant service. However, ants seldom make nests easy to find, making a thorough inspection critical. Most ants nest in soil, wood or wall voids near food and moisture sources. The nest houses the queen(s), brood (egg/larva/pupa) and worker ants.


Finding an ant nest involves the following:

  1. Find the trail
  2. Locate foraging worker ants in or around the structure
  3. Track them back to their nesting site to find the nest

Many ant species only forage at night or send the most workers away from the colony at that time. The problem is most ant inspections occur during the day. Therefore, focus your daytime ant inspections on foraging ants or trying to find nest locations in the following areas:

  • Soil areas adjacent to the structural foundation, especially around moisture sources
  • Near landscape plants where honeydew-producing insects are present (aphids, scale insects, etc.)
  • Along edges of concrete slabs abutting to structures such as patios, sidewalks and HVAC pads
  • Under or around landscape materials, leaf litter and landscape edging/elements such as boards, stones, pavers, etc.
  • In tree stumps, in piles of firewood, under wood decks and in or around the trunk/root junction of trees or other landscape plants
  • In wall voids or near leaking plumbing

Some ant colonies, like carpenter ant colonies, don’t move their nests for many years. However, other ants move their nests frequently in response to environmental factors, resource availability, dietary needs or other physical or chemical factors (such as an insecticide treatment). The depth of the nest in the soil also varies throughout the year based on these same factors.


If the nest can be located, then treatment is often easier and products (liquid sprays, dusts, etc.) can be directly applied to the nest. If the nest remains hidden, non-deterrent liquid sprays (Advion® WDG insecticide) and baits (Advion Ant gel bait, Optigard® Ant gel bait, Advion Insect granular bait or Advion Microflow Insect bait) are the best ant management options. These products are slow-acting and allow for active ingredient transfer from the foraging workers to all other individuals in the nest.


Follow these tips to enhance your ant control efforts and avoid feelings of “ant-sanity.” For more ant service best practices and product information, visit or download our ant service guidelines sheet.

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Authored by:

Tim Husen, Ph.D.
Technical Services Representative, Syngenta Professional Pest Management