Odorous House Ants

Odorous House Ants: Smelly Nuisance Ants

Odorous house ants, also known as tapinoma sessile, are a common pest found in homes throughout the United States. These small, dark-colored ants get their name from the rotten coconut-like smell they emit when crushed. While they are not known to spread disease, odorous house ants can be a nuisance and may contaminate food in your home.

If you have noticed an increase in odorous house ants in your home, it is important to take action to get rid of them. The first step in controlling an infestation is to locate and eliminate the ant colony. Odorous house ants are often found near sources of moisture, such as leaky pipes or under sinks. They may also nest in wall voids or other areas of the home.

One effective method for getting rid of odorous house ants is to use bait stations. These stations contain a slow-acting poison that the ants will take back to their colony, ultimately eliminating the entire colony. It is important to use bait stations rather than sprays, as sprays will only kill the ants that come into direct contact with them and will not eliminate the entire colony.

In addition to using bait stations, there are several steps you can take to prevent odorous house ants from entering your home:

1. Seal any cracks or openings in the exterior of your home to prevent ants from entering.
2. Keep food in airtight containers and clean up any spills or crumbs immediately.
3. Repair any leaks or sources of moisture, as odorous house ants are attracted to moisture.
4. Trim trees and shrubs away from the exterior of your home to eliminate potential nesting sites.

By following these steps and using bait stations, you can effectively control and eliminate an odorous house ant infestation in your home. For professional assistance getting rid of odorous house ants, contact us today!

Odorous House Ants (Sugar Ants)

The odorous house ant is a native ant, found in DC, Maryland and Virginia, as well as throughout the rest of the United States and southern Canada. Commonly called sugar ants, the odorous house ant is best identified by the rotten, coconut-like odor they emit when crushed. They comfortably live from sea level to higher than 11,000 feet above sea level, in almost every habitat type. The odorous house ant has been described as having the widest geographic range and greatest ecological tolerance of any ant in North America. It is a serious pest in the mid-Atlantic.

The behavior and biology of the odorous house ant depends on the environment in which the ants are located. Odorous house ant colonies may have multiple queens and multiple nest sites. They can reproduce by budding, lack aggression between nests and typically dominate the areas they invade. Colonies vary in size, ranging from small (15 to 30 workers and 1 queen) to large (500,000 workers, many queens, and many nests). Larger colonies are more common in urban areas; smaller colonies are more common in quiet, undisturbed areas.

The winged male and female reproductives mate either in the nest or after a nuptial flight, with mating within the nest between siblings more common than the infrequent mating flight. Colonies are established by newly mated queens, or by budding from pre-existing colonies. Ants from different colonies are aggressive towards one another, but ants from different nests that are part of the same colony do not fight. The duration of each stage of development varies, depending on the season of the year: 11 to 26 days for eggs, 13 to 29 days for larvae; 2 to 3 days for pre-pupae, and 8 to 25 days for pupae. Outdoors, odorous house ants spend the winter as partially grown larvae, workers, and de-alate females.

The number of nests a colony occupies changes through the seasons, and can be described by an annual fission-fusion cycle. In the winter, the colony coalesces into a few nest sites. In the spring, the number of nest sites occupied increases to occupy available nest sites and reaches the highest density in the summer. Colonies then start coalescing and return to the previous year's winter nest site.

Odorous house ants move their nests frequently, though this can vary with their habitat. In a forest, odorous house ants will move their nests more frequently than in an urban area, where they are more dominant ecologically speaking. Nests may be moved in response to adverse conditions, such as chemical or mechanical disturbance, or even rain, but they will often re-occupy the same nest site when conditions become suitable again. Odorous house ants frequently choose nest sites that are moist and shady, or are close to food.

Several factors have been identified as affecting nest number and location. Surprisingly, the density of woody plants like trees did not affect the number of nests odorous house ants would make, even though woody plants provide many essential resources for them, such as food, moisture, and potential nest sites. The abundance of odorous house ants is instead best predicted by the presence of leaf litter, logs, boards, and landscape timbers, especially when in close proximity to a man-made building.

Odorous house ant trail use changes through the seasons. In late winter and early spring, trails are used mainly for finding nest sites. As plants become established with sucking insects that produce honeydew, additional foraging trails are formed, often at the base of the infested plants. The length of an odorous house ant trail affects the abundance of nests found along it. When new nests are needed, they are typically added to an existing trail rather than extending the length of a trail.

Although nests of odorous house ants are interconnected, colony food distribution and worker movement are restricted. Workers from the same nest forage repeatedly to the same nearby food sources and while a colony may distribute food to other members in the same trail, it will not distribute the food to nests along other trails. Very few workers are exchanged with nests not connected by a trail. When applying a bait, or when using a transferable insecticide for odorous house ants, it is important to make these applications along as many foraging trails as possible.

Odorous house ants are opportunistic nesters. Nests in soil are usually shallow, and typically located beneath an object such as a board or stone. Stacked material such as lumber, firewood, bricks, rocks, and cardboard are also favorite nesting sites.

When odorous house ants invade a building, their nests are often located outside. When their nests are located indoors, their nests are usually found associated with moisture, such as within wall voids near pipes and heaters, bath-traps, wood damaged by termites, and beneath toilets.

Odorous house ants forage night and day to collect honeydew, one of their favorite foods. They also feed on both living and dead insects. They prefer sugars and protein over lipids, with no seasonal shift in food preference. Odorous house ants will forage more during the cooler times of the day and at night than during the hotter summer months. Indoors, odorous house ants are active throughout the year and will forage outdoors when temperatures are as low as 50 degrees Fahrenheit.

Odorous House Ant workers are 2.4 to 3.3 mm long, and a uniform brown to black color. As their name suggests, they can emit a rotten, coconut-like odor. They have a one-segmented pedicel. The node on the petiole is flattened, and when viewed from above, the node is concealed by the base of the ant's gaster.