Ants are amazing creatures. If you could pile all the insects in the world onto a scale and weigh them, ants would make up two thirds of the load! Their reputation as hard workers is entirely deserved: they are the principal turners of the soil, even more so than earthworms. They are also the principal predators of other insects, as well as the main scavengers of dead insects. In the words of world-renowned scientist E.O. Wilson, “Ants are one of the main balancers of the world’s ecosystems…. If there were no ants, you would really see bugs.”
Yet we all know that ants can be a nuisance. More than a nuisance: they can be a force of destruction, at least from our human point of view. We hope you never have to face anything like the man vs. ants drama recounted in the short story Leiningen versus the Ants. Yet, even a small ant infestation can quickly become serious. Once ants have established a colony on your property, they can be very hard to get rid of without the use of toxic chemicals. Therefore, if you start to notice an ant invasion, it’s important to act quickly.
Ant Bait: The Best Method of Ant Control
When you think ant control, think ant bait. Dusting some ant-killing powder around or spraying some liquid will get rid of some ants but won’t kill enough of them to prevent the colony from regenerating. It might even cause the colony to split so that you then have two colonies to contend with.
The way ant baiting works is you present the ants with poisoned food that they take home and share with all their comrades as well as their queen(s). You use a slow-acting poison mixed with something yummy that the whole colony will want to feast on repeatedly. In a matter of a week or two you have gotten rid of every single ant.
You can put together ant bait at home, but it’s a bit tricky because you need the right proportion of yum to poison. Too much poison and the ants that eat it will die before they carry it back to the colony. Too little simply won’t be effective.
Ants also vary what they eat depending on what time of the year it is and even depending on what they have already eaten. Unlike humans, they somehow know enough to eat a balanced diet: if they’ve been feasting on peanut butter for a while and a piece of fruit becomes available, they will switch over to the fruit—and vice-versa.
The first step then, if you want to create your own ant bait, is to put out swatches of several different foods that could potentially be mixed with poison and see which ones the ants are most attracted to. Then take the preferred food and mix it with diatomaceous earth.
DE is lethal to ants but entirely non-toxic to humans and pets when used according to the directions. The exact ratio of bait to DE is hard to say because it depends on the food you’re using. But a good start would be to mix it 50/50 with confectionary sugar and place a teaspoon or so in some key areas. Before you put out the bait, though, try to cut off the ants’ other food sources. The idea is to get them to concentrate on the bait.
Boric acid or borax powder can be substituted for diatomaceous earth (start with one part boric acid or borax to ten parts sugar) but these substances are slightly toxic to people and pets. And, of course, there are highly toxic pesticides that can be used against ants, but we like to avoid these, both because of the risk of accidental poisoning, and to protect the environment.
Terro to the Rescue
For those who prefer the convenience of ant bait that is premixed and ready to go, we carry an excellent Borax-based family of products made by Terro. Testimonials abound for Terro all over the Internet, such as this one by blogger J.D. Roth, which 166 people have commented on, nearly all of them confirming his praise of its effectiveness.
Terro bait stations come in both indoor and outdoor versions, and are exceptionally safe because pets and kids can’t get into them. Terro liquid can be used as the ant poison that you mix with the bait of your choice, but it is being marketed for use on wood-loving carpenter ants: you spray it on woodwork, joists, baseboards, and into any cracks and crevices where they are congregating.
This brings up the issue of some extra-tough ant species, namely carpenter ants, fire ants, and Argentine ants. To determine if you have any of these extra-tough species, view this page on the Orkin Exterminators website.
As stated above, carpenter ants can be controlled by spraying with a borax or boric acid–based solution, and also by dusting diatomaceous earth around. By the way, to learn more about the wonders of DE, check out our earlier newsletter on natural pest control.
Fire ants can sometimes be taken care of by using the ant bait tactics described above, but it might be necessary to flood their colony with an insecticide. The safest one we have found is Monterey Garden Insect Spray with Spinosad, which has been approved by the OMRI (Organic Materials Review Board). One or two applications should take care of your fire ant problem, especially if combined with some strategically placed baits as discussed earlier.
Argentine ants have particularly large colonies, sometimes numbering in the millions, with multiple queens. Nevertheless they will succumb to the ant baits described earlier made with DE, boric acid or borax. You will just have to use more of them, so if you’re ordering Terro, stock up!
The Water Cure
Finally, we’d like to tell you about a simple way to kill ants that, according to the University of Florida Extension, works 20% to 60% of the time: you boil at least three gallons of water and pour it slowly into the mound. For best result, the UF Extension recommends this be done, “on sunny, cool mornings when the majority of ants and brood are closer to the surface of the mound,” and explains that “a mound may need several treatments to reach and kill the queen and brood.”
You can try this as a stand-alone method, but we believe it is best used as an additional measure to increase your chance of success. The thing you have to watch out for, of course, is the boiling water: please be careful! Note also, that boiling water will probably kill nearby plants if it makes contact with them.
Knowledge Is Power When It Comes to Getting Rid of Ants
There’s more to say about killing ants with ant baits and by pouring insecticide and/or boiling water into their colonies—but we’ll stop here. To learn more about ant baits we recommend this fine article from the University of Florida Extension titled Ant Trails: A Key to Management with Baits. For controlling carpenter ants in your home, consult this pamphlet from Utah State University Cooperative Extension. For dealing with fire ants, the Alabama Cooperative Extension has a number of articles and streaming videos online. And for controlling Argentine ants, read this article, also from the Alabama Cooperative Extension. For more information about using diatomaceous earth to kill ants, check out this forum at the GardenWeb.
Ants are very persistent creatures—perhaps that’s why they’ve been around since before the dinosaurs. But if you are also persistent and follow the advice given in this newsletter, we’re confident your ant problem will become a thing of the past. Not that you might not have to go through the same routine again in a year or two, but we’ll cross that mound when we come to it.