Ants Invasion (Emmy, San Jose, CA, USA)


We live in San Jose, CA.

We have been reading your blog for sometime.
We are facing the ants problem.
attached pictures were just taken at a corner of my dinning room.
Hope you would help.

some ants have visited our house last year around October by crawling in from the windows to the bedrooms and kitchen.
the situation was under control after using the Terro ants bait stations; we saw less ants around.

this year, we started to see a few ants visit our kitchen counter in May.
Without knowing where their nest was, we just killed them when we saw them around.
Fortunately, they had not discovered our food cabinet yet and we have put all food in airtight container already.
Until one morning in early July, the troop found some leftover on the kitchen counter and hunderds of them paraded to the food source.
Knowing there was no use to just kill the workers, we chose to use the Terro ants bait stations again and let them enjoy the sweet fluid.
By this incident, we noticed from they came in from the tiny holes at the corner in the dinning room.
After a day, we decided to get the Terro liquid ants killer and starts to place several stations in front of the little holes as shown in the pictures right in front from where they come out.

After feeding them Terro for more than a month, they are still very active.
Hunderd of them coming out to enjoy Terro everyday.
In a hot day, which they are more active, they consumer twelve to fifteen drops of terro only within a morning and a bit less at night.
we have used up around half a ounce in the past month.

We do not want to spray pesticide inside the house.
However, sprinkle baby powder on the ant trails means asking them to walk in the walls.
and they also find a NEW way to crawl in the kitchen counter.
I need to watch carely when I prepare dinner, as they pop up all the time!

We wish to get the lemon oil or orange oil or Orange Guard from the neighbourhood stores but not successful.

Yesterday, I have lost my control as I see them again on my kitchen counter (on which I sprinkle baby powder on the side) but they finally found the opening to crawl in.

My husband bought a Hot Shot Natural with lemongrass oil and start to wipe in the ant trail.
This morning, we find less ants come out fromt the hole, while we are still placing few ant bait station in front the hole.
but the foreager still try their best to searching around.
We have consider to fill the holes, but we are afraid they will search a new opening that might be in our bedroom.

would you give us some suggestions:

1. would you please help to identify the type ants from the attached pictures? are they Argentine ants?
2. what do you suggest us to do now.

thank you very much!


from San Jose Bay Area, CA




Dear Emmy,

Thank you for the wealth of information, and I'm sorry your home is infested! Indeed, one of our experts Dr. James Trager has confirmed that these are the Argentine ant Linepithema humile, which is the most common ant in the Bay area. If you want to read more about Argentine ants, please see a few of our other posts here, here, or here.

In terms of solving your infestation problem, we get this request fairly often, so we actually have a pretty wide literature on the subject. This post is the most detailed, but you can also refer to here or here.

Good luck on getting rid of the Argentine ants!


Max Winston & the AntAsk Team

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