How To Battle Ants Without Poisons

With the unofficial start of summer, the never-ending war resumes—as millions of armored and armed invaders break into our homes and endure devastating chemical counterattacks.
“Endure” is just the right verb, scientists say, for the long-term response of ants to our frequently misapplied chemical efforts to kill and control them.
Pesticides have even given advantages to invasive ants that live in supercolonies—like the single colony of Argentine ants that covers most of California—by wiping out native competitors and by wiping out predatory species, like nematodes, that might have helped to keep them in check.
When a pesticide wears off, ants from the supercolony re-colonize the freshly cleared territory.
Ants remain the most successful species on earth. Scientists have estimated their number at ten thousand trillion—or, by another estimate—17.2 million ants per person.
And unlike persons, ants have been found to be resistant to both radiation and industrial pollution.  Ants were here 80 million years before humans arrived and, dare I say, are likely to outlive us.
So how can we best avoid them during our stay on their planet?
A few years ago I wrote a story for The Weather Channel about the “crazy raspberry ants” then invading Texas (they now live comfortably in 11 coastal counties). In the course of that story and many others I’ve written about ants over the years, I’ve had an opportunity to ask myrmecologists how we might best keep ants out of our homes. This is what they always say:
1. “Try to identify what they’re going after,” said David Holway of the University of California San Diego. “Is it food, is it some kind of nest site? If you can eliminate that, then that will largely eliminate their incentive for coming into your house.”
Chances are, the ants have come looking for one or more of three things:
“Like all pests, ants need food, water, and shelter to survive,” according to the National Park Service, which has found ants to be smarter than the average bear.
“By limiting these three essentials, you make it more difficult for ants to live in the infested area. Simply by improving sanitation you can often suppress existing populations and discourage new invasions.”
2. Cleanliness is next to antlessness: When myrmecologists — ant scientists — say ants will not be attracted to a meticulous house, they mean meticulous to ant standards. Those little nooks and crannies where crumbs elude us may offer a feast to ants.
“Frequent vacuuming, sweeping, or mopping of floors and washing of counter and table tops eliminates much of the food ants may be foraging on. Trash should be stored away from infested areas and monitored for spills.”

Enlist the aid of an anteater? Image via Wikipedia

3. Mind the gap: If cleaning isn’t your thing, sealing may do the trick, and there’s almost nothing better than petroleum jelly. Seal any cracks or crevices that ants can use to enter your house. In my experience, petroleum jelly will hold ants at bay for a year. You can use silicone caulk for a permanent barrier.
“Effective door sweeps that close the gap between the bottom of exterior doors and the door sill are essential,” said Thomas Green, president of the Integrated Pest Management Institute of North America.
4. Last call! If you live in a dry climate, ants have likely come looking for water. Scientists at UC San Diego were able to drastically reduce ant populations on irrigated land by shutting off the irrigation.
“In California, what I always tell people is stop watering your lawn,” Holway said. “Use less water and you’ll have less ants. People unfortunately don’t like to hear that, but it’s true.”
Remember that some water sources for ants can escape human notice. According to National Parks, “Ants can get their water from many sources inside a structure: condensation on pipes and air conditioners, leaky plumbing, aquariums, pet dishes, houseplant containers, floor drains, etc.”
5. Before you resort to poisons, try natural insecticides and repellants: The University of Florida maintains a list of botanical insecticides that have some environmental advantages, such as rapid breakdown. They include citrus oils, neem oil, diatomaceous earth and sulfur.
Some types of ants are also said to avoid Borax, basil, bay leaves, catnip, cayenne, cinnamon, coffee, camphor, peppermint, vinegar. Be advised not all may deter your invaders.
“Often that’s very species specific, so what works for one ant might not work for another,” Green said.
It’s worth trying natural deterrents before chemical not only because ants seem to thrive in the aftermath of poorly applied chemicals, but also because humans and other animals don’t.
Beyond Pesticides maintains a database of studies that link pesticides to human illnesses including cancer, asthma, autism and learning disabilities, birth defects and reproductive dysfunction, diabetes, Parkinson’s and Alzheimer’s diseases.
If you must use a chemical, look it up first in the Pesticide Action Network (PAN) Pesticide Database. In many cases, you may find that its effects are unknown.

http://blogs.forbes.com/jeffmcmahon/2011/05/30/how-to-battle-ants-without-poisons/?partner=contextstory