Ant Baiting Tips

04/2022 Issue: Ant baiting tips

By: Joshua Villazana, M.Sc., Dynamic IPM Specialist

In the insect order Hymenoptera, there are approximately 13,500 different species of social insects, including bees, ants, and wasps. For ants alone, there are about 9,500 different species globally, and of those there are over 700 different ant species found in North America where, 25 are commonly found in structures. Furthermore, five are public health threats and potentially dangerous to humans.

Pathogen transmission risk. When dealing with ants: bites and stings are something that pest management professionals (PMP) may unfortunately be familiar with. However, there is also potential for ants to transmit pathogens. This is especially important when planning to prevent ants from entering food plants. The pharaoh ant (Monomorium pharaonis) can transmit over a dozen pathogens such as Salmonella spp., Staphylococcus spp., and Streptococcus spp. (Beatson 1977; Haack and Granovsky 1990; Smith and Whitman 1992). All ants have the potential to be a source of food-borne illness because their nesting or foraging habits can contaminate food and packaging in food plants. Nest disturbances can cause a colony to migrate entire nests and can sometimes enter a semitruck with food products.

Ant encounters. The type of ants found in a food plant will vary based on geographical location and available resources. Some notable ants commonly encountered are the following.

• Carpenter ants (Camponotus spp.) will create galleries in wooden pallets or may harbor in voids of containers with product such as, cardboard boxes or products where ants have been foraging for food.
• Pavement ants (Tetramorium caespitum) can wonder through cracks in floors, expansion joints, and can be attracted to food spills inside or outside the building when foraging.
• If wood mulch is used around exterior areas of buildings. Odorous house ants (Tapinoma sessile) will build nests under mulch, rocks, or leaf litter, and have the potential to be brought in on mulch deliveries.

Ant bait considerations. Baits are an effective form of ant control since they take advantage of ants’ social characteristics. Palatability and environment are major factors to consider when selecting a liquid, gel, or granular bait formulation to be attractive to foragers so they will ingest the bait and share it within the colony. A granular bait would typically be used on the exterior close to the perimeter and a gel or liquid on the interior. Since baits tend to be slower acting than other forms of ant control; the delayed activity of the toxicant is key to ensuring distribution throughout the ant colony. There is a higher chance of getting ants to be attracted to a bait and taking it back to the queen vs. a pesticide spray that would kill the workers but not the queen, allowing them to return.

Feeding habits. Gaining insight into the feeding habits of the ant swarm identified can help a PMP apply the right treatment protocol. Ants’ feeding habits change depending on the time of year and the availability of various food sources. In spring and early summer, brood care is high in the colony. Therefore, ants require large amounts of protein, so they will forage for arthropod prey. Later in the summer, the colony pursues carbohydrates to provide sustained energy within the colony. For example, Pharaoh ants (M. pharaonis) enjoy sugars, proteins, oils and insects. Odorous house ants (Tapinoma sessile) like sugars and protein and Carpenter ants (C. spp.) prefer sugars and insects.

When unclear about which bait to use, prebaiting can save time and effort. With the use of a protein, sugar, or arthropod source, a PMP can use peanut butter or non-peanut substitute, jam or honey, ground insects, and oils on several insect glue board or tape to help determine which type of food the ants in question are most drawn to and can also help identify areas of heaviest activity and nest location.

Final thoughts. Baiting is a powerful strategy for several reasons. Baits are pesticide applications that rely on the pests themselves. Since it is considered a food source to ants, they gladly take in the bait that will terminate them unknowingly. When possible, be sure to ask staff to remove alternate food sources and place the bait in areas where ants are active. This will help focus the ants on your bait. It is in the ants’ interest to work together for maximum efficiency so, when baiting them make sure to use the appropriate type of bait, don’t make them hunt for it, and use enough to get the job done.

Work cited

Beatson SH. 1972. Pharaoh ants as pathogen vectors in hospitals. Lancet 1: 425–427.

Bennett, G. W., Owens, J. M., Corrigan, R. M., & Truman, L. C. (2010). Truman's scientific guide to pest management operations. North Coast Media, LLC.

Haack KD, Granovsky TA. (1990). Ants. In Handbook of pest control. Story K, Moreland D (editors). Franzak & Foster Co., Cleveland, OH. pp. 415–479.

Photo by Peter F. Wolf on Unsplash.com

Smith EH, Whitman RC. 1992. Field guide to structural pests. National Pest Management Association, Dunn Loring, VA.