Hints for Homeowners…
Fire Ants in Winter?

Lisa Lennon, Extension Agent, IPM—Fire Ant Project
Travis and Williamson Counties
Texas Agricultural Extension Service

Winter in Central Texas does not necessarily mean snow and ice, but it can mean days of painfully cold temperatures.  Fire ants in winter may not be easily noticed.  However, the pests remain in the soil and continue to cause problems for those spending time outdoors, whether or not they are visible above ground.  Fire ants are generally less active during the winter months but occasionally may mound following winter rains or warmer periods when daytime temperatures rise above 70 degrees.  It is not uncommon to find fire ant mounds along curbs, near parking areas, sidewalks, or structural foundations where the ants take advantage of solar radiation from the concrete and moisture from irrigation run-off.

Fire ants’ food preferences change periodically, especially during the winter and summer when the queens’ egg production slows.  In the winter, the ants typically do not seek out the high protein oily foods as they do in warm weather.  Due to this change in food choice, bait-formulated products (Amdroâ, Logicâ, or Spectracide Baitâ) are generally are not effective.

Individual mound treatments, or spot treating, are more effective during the winter months.  Products for individual mound treatments vary in their formulations and active ingredients.  Examples include:
Dry formulations are typically granules of either diazinon or dursban products.  However, improper use of these products causes problems in surface run-off, which can contaminate area lakes and streams.  As individual mound treatments use these products sparingly and completely drench the mound by using one to two gallons of water.   Follow label directions for the specific product used.
Acephate (Ortheneâ) dust formulation, a relatively quick acting contact insecticide, are less harmful to aquatic animals and usually do not create runoff problems.
Liquid formulations are common and contain a variety of active ingredients.  “Organic” type products (Organic Solutionsä) usually contain pyrethrin, or rotenone.  Some contain diatomaceous earth (an inorganic compound).
Many other formulations are available; check that ‘fire ants’ are listed before use.
For best results using individual mound treatments, do not disturb the mound.
Always read and follow label directions before using any pesticide product.

For more information on fire ants and their management, contact Lisa Lennon at the Travis or Williamson County Extension office.

Information herein is for educational purposes only.  Reference to trade names is made with the understanding that no endorsement by the Texas Agricultural Extension Service is implied.

For free information, contact Lisa Lennon at the Travis or Williamson County Extension Office:
(512) 473-9600, e-mail li-lennon@tamu.edu.

For our other articles posted by VNA on control of fire ants, see:
fireants.html   and   fireant_hints.html

For even more information on combating fire ants, see:

For general insect info, see the Texas A&M Department of Entomology main page at:

Educational programs of the Texas Agricultural Extension Service are open to all people without regard to race, color, sex, disability, religion, age, or national origin.

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