The Odorous House Ant (Tapinoma sessile) is a native species, found throughout the United States. It earns its name by producing a foul, "rotten coconut" odor when crushed. The Odorous house ant, found throughout the US, is a particular problem pest ion the West coast, Atlantic coast, and New England areas. Odorous House Ants and Argentine ants often do not exist in the same location. Argentine ants can quickly drive out Odorous ants in an area. Along with the Argentine ant, Crazy ant, Pharaoh ant, Ghost ant, the Odorous ant is considered a "tramp" ant. They can move from place to place and live in close association with humans, becoming a significant nuisance. They have multiple queens and multiple colony sites.
Courtesy of University of Nebraska-Lincoln
The workers are about 1/16–1/8-inch (2.4–3.25mm) long. The body is brown to black in color. The antennae have 12 segments.
Females in the nest lay one egg daily. It takes an average of 24 days for the young to reach adulthood. Colony size ranges from 100 to 10,000 ants. Their large colonies contain many active queens.
Ant Trails: Odorous ants as well as other ants lay down a chemical trail of pheromones. Ant trails occur between nest sites and food sources. When baiting it is important to look for their trails and place the bait there. They forage day and night. Workers forage along established trails. Look for their trails and possible nest sites.
Nests: The nests can occur in a great variety of situations. Inside, these ants usually construct their nests in wall voids, especially around hot water pipes and heaters, in crevices, sinks, cupboards, etc. Outside they are found in exposed soil, usually shallow, often located beneath a board, brick, stone walk, etc. They form nests in cavities of trees and loose bark. Nests can be found in bird nests and animal nests. They also like to nest on top of honey bee hives for the warmth provided.
They are most likely to enter buildings when their honeydew supply or sweet supply of food is reduced by natural occurances such as rainy weather or autumn leaf fall.
They can feed on anything such as insects, honeydew, seeds, and plant secretions, but do prefer sweets. They are extremely fond of honeydew and attend such honeydew-excreting insects as plantlice (aphids), scale insects, and mealybugs.
- Remove any grease or crumbs and wipe down counters and kitchen floor.
- Move woodpiles away from exterior walls and seal up any cracks and crevices.
- Trim branches or trees that may be touching your house, so they don't use them as a highway into your home.
- Since these ants are attracted to water, fix any leaky faucet or moisture problems.
How to Get Rid of Odorous Ants
Treat the exterior perimeter with a non-repellant insecticide like Taurus SC. Spray a coarse mist of Taurus SC around the base of the foundation. Spray a foot up the wall and a foot out from the wall. Spray 18-inch bands around all window, doors, and plumbing, utility penetrations and along any visible ant trails. It can't be detected by the ants, so they crawl through it and unknowingly track it back to the nest and queen, killing all. We recommend the use of ant baits indoors, especially in cold weather where ants won't travel outside as often. A gel bait like Optigard Ant Bait Gel is very effective.
Unless you use a non-repellent spray such as Taurus SC or FUSE , baiting is the preferred treatment over typical residual spraying of repellent insecticides. Baiting is the most reliable way to eliminate the entire colony. When choosing Ant baits, it is best to choose from both the sugar-based baits and protein/grease-based baits. If using a spray, choose a non-repellent type unless you are treating the nest itself.
Why Ant Bait?
The use of residual sprays or dusts stress Ant colonies, causing them to split into sub-colonies and scatter. This scattering, also called budding, multiplies the number of Ant colonies, and thereby multiplies your Ant problem.
When you bait, use a slow-acting bait. Quick-kill insecticides and baits will only kill the foraging Ants, not allowing those worker Ants to take the bait back home to feed the queen, nest workers, and brood.
If the Ant bait that you are currently using is not effective (if the Ants are not visiting the bait) you will need to change the baits. Slow-acting baits provide a variety of the foods the Ants find in nature. Examples are: other insects (proteins/grease-based baits), nectar, aphid honeydew, and plant products (sugar and carbohydrates found in sweet-based baits).
Choosing a bait requires an understanding of the nutritional needs of the colony. To be sure that you have all the baiting needs met, you may want to be ready with a sugar/carbohydrate-based bait, a grease/fat-based bait, and a protein-based bait.
IMPORTANT NOTE: REMOVE ALL OTHER FOOD COMPETITION WHEN BAITING AND LEAVE THE BAIT ALONE ONCE THE ANTS START FEEDING ON IT.
Recommended Odorous Ant Baits
(Sweet and Protein/Grease Feeding Cycles)
When in doubt of which one to choose, choose one from each category.
- Top recommendation from the protein/grease category is Advance 375A , followed by Invict Xpress
- To recommendation from the sweet feeding category is Advion Ant Bait Gel, followed by Optigard Ant Bait Gel.
Protein /Grease feeding cycles
Sweet Feeding Cycles
Non-Repellents For Outside and Inside Odorous Ant Control
Spraying for Odorous Ants with Non-Repellents
You would spray on the outside with Taurus around the perimeter. Usually spraying the perimeter is enough treatment for Odorous Ants, as they will go outside. If you need any insecticide inside, use Phantom Aerosol in cracks and crevices.
Non-Repellent insecticides are best for ants and termites, because these insects can not detect it and will not try to escape the insecticide. Non-repellent insecticides can't be smelled, tasted, or even felt by Odorous Ants.
Another advantage for using a non repellent insecticide such as Taurus or Phantom for Odorous Ant Control, is that you can use ant baits near it. Repellent insecticides do not combine well with insect baits, because they contaminate the lures inside the baits; that is not the case with non-repellents.