How to Prevent Grease Ants

These ants like greasy no-good-for-you foods.

Ants can be pesky intruders in your home. They may be unwanted guests looking for shelter from inclement weather, but a more likely explanation is that they've located a food source worth exploiting somewhere in your house -- and they will exploit it until all the food is gone. In the case of grease or "thief" ants, that food source is probably high in protein. Grease ants eat meat, oil and fat. They'll also consume some foods your kids may have discarded under the bed or accidentally dropped behind a couch cushion like peanut butter sandwich crusts, ice cream dribbles or cheese snacks.

Grease ants can be particularly difficult to control because they're ingeniously persistent once they tag a home as the corner deli. They're also tiny, about 1/16 of an inch in length which makes them miniature Houdini impersonators when it comes to exploiting small cracks or holes that allow them to get in and out without detection. Their small size and pale coloration (tan to brown) can also make it hard to spot them until there's a full blown ant offensive zigzagging its way across your kitchen floor on a march from Fido's bowl to home base.


That home base could also end up being inside your house. Grease ants can take up residence in dark cupboards, under countertops, behind baseboards and in other out-of-the-way spots. They like rotten wood best, but they're adaptable. If you have something edible around, they'll be happy to settle in for the duration. They can even expand their culinary repertoire to other foodstuffs if protein options become scarce. Once established, they're hard to eliminate. That's why it's a good idea to avoid problems with grease ants in the first place. Here are some tips how to get rid of ants and keep these thieving insects outdoors where they belong:

  • Eliminate potential food sources -- Grease ants prefer a high protein diet. That translates to tasty items like the grease that accumulates on your stove hood and around your oven door. No kitchen is spotless, but the cleaner you keep your home, the less appealing it will be to ants. There's an upside to ant-proofing your house. Keeping areas where food is prepared and eaten cleaner will reduce the risk of bacterial contamination and foodborne illness.
  • Seal cracks -- This can be a tall order because grease ants are so small, but finding and sealing cracks, gaps and holes around your home is always a good idea. If you notice numerous cracks, it will alert you to potential structural problems on your property, too. Sealing cracks will also reduce heat loss (and result in energy savings) during the winter months. Seal large cracks with caulk. For tiny cracks or suspected cracks, use a dab of petroleum jelly. Grease ants won't eat it, and it makes an effective barrier. Ants don't like wading through goo any more than you do.
  • Put down bait traps -- If you know grease ants are active around your property or neighborhood, you can be proactive and place bait traps outdoors. There are a number of varieties on the market, but be careful to stick with baits that attract grease or protein-loving ants.
  • Hire an exterminator -- If you have an ongoing battle with sweet-loving ants, there's a chance their presence on your property or in your home will attract grease ants, too. Grease ants like to establish colonies near other ant nests. You can try to handle the threat yourself or hire an expert. Exterminators will usually put down bait traps and may also locate and destroy established nests. This is an effective, permanent solution, especially during the summer months when grease ants are likely to be the most active.


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Related Articles

  • Iowa State University of Science and Technology. "Grease Ants." 2005. (7/17/12).
  • Kimball, Cheryl. "Outwitting Ants." Global Pequot Press. 2002.
  • Ogg, Barb. "Ant Baits: A Least Toxic Control." University of Nebraska. (7/17/12).
  • Orkin. "Grease Ants." (7/17/12).
  • Terminix. "Thief Ant." (7/17/12).
  • University of California - Davis. "Thief Ant—Quick Management Tips." 2011. (7/17/12).
  • University of Nebraska. "Thief Ant (also called "Grease Ant")." (7/17/12).