Odorous House Ant


Often confused with the pavement ant, the odorous house ant is a native species found throughout the United States. It earns its name by emitting a foul odor when crushed.

Fast Facts

Color Appears uniformly brown to black.
Size Odorous house ant workers are all about the same size. On average, the ants range from 1/16 – 1/8″ in length.
Appearance All odorous house ants possess a head, antennae, an uneven thorax, and an abdomen. These ants do not have stingers and are unable to bite.


Sugar serves as the main source of sustenance for the odorous house ant. They prefer sweets, like fruits, honey, pastries, and syrup, but will eat almost any household food. Honeydew produced by other insects, particularly aphids remains a staple in the diet of the odorous ant species. Protein in their diet is typically obtained from feeding on very small insects and their eggs, such as springtails.


Indoors, the house ants nest in wall and floor voids, especially around hot water pipes and heaters, and in crevices around sinks and cabinets. Outdoors, nests are often found in soil, typically under stones and logs.

Colonies & Life Cycle

Ants swarm to mate from early May through mid-July; they also mate within the nest, forming new colonies by “budding” off the original colony. Depending on the area, odorous house ant colonies range in size from small to extremely large. A colony typically has 10,000 workers and several queens, each laying one egg per day. Smaller colonies range from 15 to 30 workers and include a single queen, while some of the largest reported colonies swell to as many as 500,000 worker ants and feature several queens. As a result, larger colonies tend to maintain several nest sites. Developmental time from egg to adult is 34 to 83 days. There are several generations per year and workers and queens live for several years.

Damage & Signs of Infestation

Odorous house ants don’t transmit diseases and aren’t capable of biting. Most problems caused by odorous house ants center on their preference for sugary foods and their willingness to forage in kitchens and pantries. The pests generally invade homes in large numbers and are therefore considered a nuisance.


Watch for adult ants in later winter to early spring.


Finding a nest also clearly reveals an odorous house ant problem. Indoor nests may appear in wall voids close to pipes or heaters, wood damaged by termites, or beneath toilets. While outdoor nests tend to be under leaf litter, boards, landscaping timbers, piles of lumber or firewood, bricks, rocks, cardboard, and similar debris.


When crushed, odorous house ants emit an aroma similar to the smell of rotten coconuts. The unpleasant scent is usually noticed when a nest is discovered or the ants are crushed.


Look for damaged food storage containers, especially those holding sugary foods. Spotting adult ants in food supplies usually points to the existence of a home infestation.

Prevention & Control

Odorous House Ant Prevention

The key to prevention centers on creating an unfavorable environment for odorous house ants. This can be achieved by:

  • Caulking or sealing any cracks in the foundation or around doors and windows.
  • Follow proper sanitation practices to discourage odorous house ants from invading.
  • Seal foods in airtight and ant-proof containers.
  • Keep trees and shrubs well-maintained, and avoid letting the vegetation come into contact with the outside of the home.
  • Clear any debris that would make a suitable nesting site for the pests.
Odorous House Ant Control

Soapy Water: Since odorous house ants leave chemical trails while scavenging, sponging the foraging adults with soapy water reduces the likelihood of more ants returning.

Baits: Baits work as long as they target sugar-loving ants.

Exclusion: All cracks and gaps within exterior walls that provide access to voids or interior areas should be sealed. Remove all debris from the exterior of the structure where nests could be formed. Baits should be placed where ant trails have been established or in locations where the ants have been sighted. Follow ant trails and locate nests – treat with residual insecticide.

Call the Experts: Odorous house ant infestations that involve an indoor nest or multiple nesting sites often require the help of a pest control professional. The use of insecticides may prove necessary for control and professionals possess the experience, training and proper certifications to manage these pests.