Reporter's Notes: Coping with Ants at Home

Lauren Sommer Post on Feb 19, 2010 by
Topics: Biology

Image Credit: Alex Wild.

For those of us fighting losing battles against them in our kitchens, ants are just ants. But the species responsible for the majority of those invasions has a name: the Argentine ant.

Argentine ants have had amazing success as an invasive species in the US. Their West Coast super colony numbers in the billions and spans from Mexico to Oregon. But aside from invading homes, they've had a dramatic effect on native ants and local ecosystems.

While many of us may not think ants are particularly important, ants hold a number of key ecological jobs, as I learned in this week's story. They disperse seeds, aerate soil just like earthworms, and recycle nutrients just like nature's garbage men (well, garbage women. Worker ants are actually female). For more on ants throughout the world, check out this QUEST TV story.

 

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Listen to the QUEST radio story Bay Area Ant Invasion

 

Argentine ants are certainly tiny, but thanks to their numbers, they've out-competed native ants for resources and attacked their colonies. So, many of the ecological jobs that native ants do are disappearing. Scientist have also documented the decline of coastal horned lizards, which depend on native ants a food source.Check out an interactive map of native ants.

Citizens are helping track Argentine ants and their impact on native ants through a citizen science project, the Bay Area Ant Survey, run by the California Academy of Sciences. You can find more information on how to submit ant specimens of your own here. And for a little more about how they're collected, check out this post by QUEST's Jessica Neely.

In their native range in Argentina, these ants aren't such a nuisance. They don't form the super colonies that we see in North America. It's almost a terrible ecological irony: since the ants in the US descended from a small group introduced by humans, they're genetically similar. So, colonies that would normally fight over resources now see each other as relatives. With no ant wars, they've put that energy into expanding.

So, what can we do when Argentine ants show up in our kitchens?

I asked the two scientists I interviewed for this story and their answers were pretty fascinating.

First, Cal Academy's Brian Fisher on the use of chemicals:

Second, UC Berkeley's Neil Tsutsui on what makes our homes look so good to ants:

Listen to the Bay Area Ant Invasion radio report online.


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  • Jane Craig

    I've battled argentine ants for 16 years in my home. I'm compulsive about keeping food sources out of reach, have tried plugging holes they come in (pretty useless by the way), and usually resort to a boric acid, sugar water solution. In about a week or two it knocks them back for a while. Sure they eventually come back, but it's better than other chemicals.

    These ants are voracious and will attack and eat just about any insect. I really can't wait to have a more effective tool in order to have a small trickle of ants in my house. As of now, there are hundreds at any given time.

  • Diana Pray

    I've successfully managed ant invasions by "blinding" them with odor: cedar wood oil sprayed directly into the cracks and holes through which they enter my home. I follow the trail back to the source (wiping up the ants as I go) and spray into their entry point. In nearly 10 years in my century-old San Francisco apartment (impossible to seal), I've never seen ants return via a sprayed entry point. Mix the oil 1:1 with rubbing alcohol (this spreads the spray more effectively, dries faster, and prevents the oil from clogging the nozzle). Don't like cedar? Use peppermint oil.

    Boric acid does work (albeit slowly, and on only a few hundred of many thousands colonizing under your home), but it is not safe for household pets. Strong-smelling oils like cedar wood and peppermint don't harm you or your pets. Avoid using commercial perfumes or colognes, which are filled with components that we really don't want on our bodies, in our homes, or washed into our water.

    The other thing to keep in mind is co-habitation. As stated in this report, these ants do not want to be in our homes; they'll leave when the weather changes. Keeping a clean home (especially kitchen and bathroom) prevents the horrifying invasions of thousands, and with nothing to eat, the few who come in for a little shelter won't stay for long.

  • Debi

    I've had pretty good luck using caulking (I like the clear stuff). We used to get tons of ants, and over the years there've been fewer & fewer, as I get their entrances plugged up one by one.

    And I use "Grant's Kills Ants" ant bait when I'm having trouble figuring out how/where they're getting in.

  • Doug

    We have tried many deterents other than poisons because we don't kill. The most effective solution for us has been to give them what they want. We stream lines of honey on overturned plates (covered to shield from rain) outside likely entry points. Our commercial kitchen that previously had thumb wide
    highways of ants has not had more than a few scouts in the three months we have used the honey
    attractors. 99% success thus far.

  • http://www.solveeczema.org A.J.

    I found that completely obliterating their scent trails gets ants to leave and never come back. They'll still come in for awhile, following an initially hot trail, fumble around lost — then it seems they must leave some kind of warning because they don't come back, no matter what temptation I leave around.

    This has worked for me for decades in numerous localities. I wrote about it on my blog — though I have to finish the final part of a three-part series, the first two parts may be enough to go on for anyone interested. It's very difficult to find things that really do eliminate the scent trails, very difficult. (I have found only one among dozens of common household substances.) However, once that is accomplished, it's possible to wash the scent-eliminating substance off with ordinary soap, the result is the same.

    http://solveeczema.wordpress.com/2008/02/01/off-topic-how-to-get-rid-of-ants-for-good/

  • http://www.darlowsmithson.com Rebecca North

    ANIMAL PLANET SEEKS ANT INFESTATION CASE STUDIES

    Hi,

    My name is Rebecca and I'm a producer on a new series for Animal Planet called 'Extreme Infestation'. I'm looking for people who are currently battling argentine ant infestations in their homes.

    Extreme Infestations is a series that looks at the 'natural history' of pests infestations in homes. If you have had – or are having – an ant infestation please contact me – Rebecca North – at rebecca.north@darlowsmithson.com. I'm based in London, but can call you back if you supply a number.

    If this is happening now and you have access to a video recorder of any kind (HD is best) please film the problem at its worst – we will use it!

    I hope to hear from you soon…

    Many thanks,

    Rebecca

    Producer
    Extreme Infestation for Animal Planet
    Darlow Smithson Productions
    rebecca.north@darlowsmithson.com
    +44 (0)207 482 7027

  • Pingback: Producer's Notes: Ants: The Invisible Majority | QUEST Community Science Blog - KQED

  • JLP

    Averse to chemical solutions, I experimented with a number of essential oils, and found cinnamon oil to be the most effective deterrent against ants. Sometimes I used it directly to efface their trails, other times mixed with detergent in a spray bottle to kill them on contact and saturate the holes from which they were entering. The only downside is that they're good at rerouting, so you have to stay vigilant and keep reapplying it.

  • Niko

    Here is a video of a man who has found many uses for mushrooms including getting ride of ants. he used them for carpenter ants but i can see Argentine ants being next on the list. i put the video code in but if that doesnt work i included a link to the video at the bottom. here is also a link to the article. http://www.conservationmagazine.org/2009/01/the-mushroom-messiah/
    and if your too lazy for all of that than i pasted the specific part of the article with ants as follows, but check out the whole article it is really great.

    3. Ants on ’Shrooms

    When carpenter ants invaded Stamets’s home, he didn’t call Terminix. Instead, he went to his lab and engineered an insect-eradicating fungus.

    His experiment rested on a long-known fact: certain fungi can infect and kill ants and termites. But, to protect their colonies, these insects have devised morbid ways of preventing fungal poisons from spreading. Ants, for example, will identify an infected individual, then decapitate it or isolate it in a side tunnel. Companies have tried for years to come up with fungal killers that subvert these defenses. Those efforts were largely unsuccessful—until Stamets developed an ingenious solution reminiscent of the Trojan horse.

    Stamets developed a fungus that is not only deadly to ants but also waits to form spores. Since ants don’t see spores when they encounter the fungus, they don’t identify it as poison. Rather, they actually mistake it for food and carry it back to their queen. By the time the fungus sporulates, it’s too late to fend it off. The fungus has already spread throughout the colony’s ants.

    Stamets has received several patents for the fungal pesticide and says just five grams of the stuff can wipe out a home infestation. Even better, he claims the nontoxic solution is harmless to humans. Still, Stamets has to work out a few kinks before the product can hit the mass market.

    Roger Gold, professor of urban etymology at Texas A&M, points out that it’s hard to maintain unique fungal strains over long periods of time, which could make it hard to scale up production. Stamets will also need to navigate the EPA’s approval process, an enterprise that can cost millions of dollars. He says he’s had interest from investors who might foot the bill, but he admits that some of them become hesitant once they take a closer look. Ever the contrarian, Stamets interprets those doubts as reassurance that he’s on the right course. “The fact that there are people who say this will never work is proof I’m onto something unique and novel,” he says.

    http://www.ted.com/talks/view/lang/eng//id/258

  • http://www.kqed.org/quest Jenny Oh

    Dear A.J. – I added the link for you.