The Odorous House Ant

A friend of mine has had a long running problem with tiny ants in her home.  She has tried cleaning and baits, two of the most effective methods of ant, and other household pest, management.  Though regular cleaning is probably the best way to prevent new infestations, it often needs to be boosted by other methods when trying to manage already established pests.  This of course, depends upon what you consider a pest…but I won’t get into that here.

As with any pest, properly identifying the pest is important.  For example, bed bugs, a genus of insect which has seen a resurgence over the last ten or so years, is quite similar to the bat bug.  The only way to really tell the difference between the two is to look under a microscope and check out their hair!  Bat bugs have slightly longer hair on their chinny-chin chins.  Why does that matter?  Because bat bugs and bed bugs require different chemical and mechanical treatments to thoroughly treat them; not to mention different legal implications…but that’s another post.

Ants are similar in terms of control methods.  The type of species you have will dictate how you treat them.  One of the most common ant pests of the indoors of human dwellings is the Odorous House Ant (Tapinoma sessile [Say]).  These are a native species of ant and are distributed throughout the vast majority of North America from Mexico into Canada.  Workers, the ones you will most likely see wandering around) are quite small, averaging about 2mm to 3mm (1/8th inch) in length.  If you want to positively ID them yourself, check for 12 antenna segments, 10+ teeth on their mandibles and most importantly, the petiole (the bit connecting the thorax to the abdomen) is quite distinctive and will not have a node, whereas most other ant species will.

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Notice that the smooth little "tube" from the thorax (part where the legs are) to the abdomen (big bit at the end). That bit is called the petiole and in this species, is "nodeless".

Or, you can just squish it in your fingers and see if it smells like a weird almond-coconut goo.

Okay, now that you can ID them (because I know you really wanted to know), next you need to deal with them.  These guys feed primarily on sweets and fats which is why you find them in kitchens for the most part.  As stated earlier, CLEANING is a must.  However, cleaning has to happen in the right places.  These ants leave trails, so if you clean the trails without killing the colony, the ants will just make new trails.  Determine which points are high traffic areas for the ants.  Place the bait right near those areas.  For the Odorous House Ant, make sure they are slow-acting.  After all, if they die before making it back to the queen, there will be no effect as she will just keep producing.  According to the University of Nebraska, the best baits are those with boric acid or hydramethylnon as their active ingredient.

It might also be advisable to hire a pest control professional to have do a preventative spray around the outside base of your home.  However, this will depend upon the severity of your pest problem and ability to treat on your own.  Contact your local extension office (typically out of universities, specifically Land Grant Universities) for best options.

Try to be careful about your choice of placement.  You don’t want to put a bait near your cat food for instance.  Please check out the following sites I used to compile this information.  They have some great recommendations for treating these and other ant species.  The UN-Lincoln page also has a neat way to determine where the best locations for bait placement should go.
University of Nebraska-Lincoln

Washington State University Extension Bulletin 1550E

For more information and images on the Odorous House Ant, check out BugGuide!


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