Ant Month: Meet the Odorous House Ant

Ant Month: Meet the Odorous House Ant

In the third of our Ant Month series (check out the Argentine ant and fire ant if you missed it), we’re focusing on one of the species you’re most likely to encounter here in the United States—the odorous house ant.


COMMON NAMES: House ants, sugar ants, stink ants, coconut ants, and OHAs

LATIN NAME: Tapinoma sessile

ORIGIN: Odorous house ants are native to North America, spanning all the way from Canada into Mexico.


  • These ants have an insatiable sweet tooth (which is why they’re often referred to as “sugar ants”), but they will also feed on dead insects and grease.
  • Odorous house ants get their name from the odor they emit when crushed. The smell is often likened to rotten coconut, pine-based cleaners, blue cheese, or rancid butter.


  • Odorous house ants are small—only about ⅛ of an inch. Five of these worker ants could stand head to abdomen and be no longer than the average aspirin pill.
  • These ants are typically dark brown, sometimes appearing shiny or black in color.
  • Workers are uniform in color and size.
  • Odorous house ants have a prominent abdomen that conceals a single petiole node. Their armored bodies have two antennae, six brownish legs, and an irregularly shaped thorax.
  • Odorous house ants are often mistaken for adolescent pavement or Argentine ants.


  • Odorous house ants are highly motivated by sweet substances, favoring nectar and honeydew (a thick, sweet substance found in the wild and produced by sap-loving insects such as aphids).
  • Indoors, foraging worker ants are on the hunt for sticky spills, fruits, juices, and the sugar- or carbohydrate-filled foods commonly found in pantries.
  • Because of their adaptability to a variety of conditions, odorous house ants are also known to eat processed foods, meats, dairy, vegetables, grains, fruits, and dead or decaying insects.



Odorous house ants don’t have complex needs when it comes to creating nests and can be found within wall voids, near appliances, around pipes, or tucked away in cabinets, pantries, and baseboards. These pests favor damp areas to build their nests, so leaking pipes or areas with higher humidity are more likely to host an ant colony.

Odorous house ant colonies build nests (or even relocate them) indoors when an abundant food supply is discovered nearby. This food supply is, unfortunately, often found in the spills or crumbs on the floor, fruits and sweets on the counter, and packaged foods stored on our shelves. The odorous house ants you catch trailing on the floor are following an established pheromone path, an invisible scent trail left by foragers intended to guide fellow workers to and from food sources.


Odorous house ants typically build large colonies, but their nests don’t have the prominent mounds or complicated tunnel systems that other ant species create. Instead, odorous house ant nests are typically established in shallow soil, most often underneath stones, piles of wood, beneath logs, or under pathways. Very few locations are off-limits for these pests, meaning sandy beaches, garden mulch, forests, structures, and even other animal nesting sites can host their colonies.


Odorous house ants can contaminate food and the surfaces of your home while foraging for their next bite. In laboratory studies, some odorous house ant workers were discovered carrying more than a few harmful pathogens.

Bites from these ants are very unlikely, and since their abdomens are stinger-free (unlike fire ants) you don’t need to worry about being stung by odorous house ants. Largely a nuisance pest, these ants multiply quickly, and an infestation can grow to large numbers in a relatively short amount of time.


  1. Without a guaranteed food source, these ants won’t have a reason to stick around. Cleaning up spills, properly storing food in airtight containers, and wiping down sticky surfaces will discourage odorous house ants from coming inside and contaminating your food.
  2. Observe the ants’ migration to determine where their nest is located. Check the exterior perimeter of your home, pausing to inspect any cracks or gaps around foundations, doors, and windows, and take a close look at landscaping that could be acting as a bridge into your home.
  3. Find and seal any small holes or cracks that can serve as entry points for these pest intruders. Many cracks can be repaired with caulk or insulation foam, while worn out weather stripping and door sweeps should be replaced with new material.
  4. Indoors, when you spot a trail of odorous ants, eliminate their pheromone trail to prevent the ants from finding their way back. You can do this by wiping the area down using an ammonia-based cleaner such as Windex. The ammonia will help disrupt the scent trail.
  5. For larger infestations, a pest control professional can help determine the best type of bait that will work with the invading ant colony. Some odorous house ant colonies respond better to sugar-based baits, while other times protein-based baits are more effective.


Ant control, regardless of species, is an ongoing process, and infestations can become overwhelming very quickly. Our pest control professionals are trained to identify and manage odorous house ant invasions, as well as provide support for other pest issues your home and garden face.

DIY ant control doesn’t need to be a bunch of guesswork, and our Ant Month series is here to guide and support your ant control efforts. Check back next week for another ant species spotlight, and if you’d like additional support, give us a call to talk to one of our experts to build a unique pest control plan for your home and garden.