Ant Control

In Carl Stephenson’s classic short story “Leinengen Versus the Ants”, the reader is forced to white-knuckle the text as a massive host of ants threatens to devour every man, woman, and animal on a cattle ranch. Indeed, ants are a common insect enemy in the world of science fiction. Perhaps this is because of the caste system – the workers, soldiers, and queens - that makes up an ant colony. Perhaps it is both the ants’ organization and almost alien-like abject single-mindedness toward a common goal. Whatever the case may be, in reality, ants usually pose little threat to humans and are actually beneficial in many ways. Ants in and around the home will deter and kill off termites, bed bugs, flea and fly larva, and other serious household pests. Ants are also decomposers, and they help aerate our soil.

However, a few ant species are serious pests. Carpenter ants can cause structural damage when they hollow out rotting wood to make room for their colony. Fire ants can inflict painful stings which can be serious for sensitive individuals. These ants deserve their own Simple Pest Control article, and they shall have one. This article covers the general principals used to control the hundreds of other common pest species of ant - the pavement ant, pharaoh ant, thief ant, Argentine ant, odorous house ant, little black ant, harvester ant, and more. Below you’ll find a variety of strategies that, when used together, will effectively control ants in the home, yard, and garden.

Behavioral Control: Sanitation and housekeeping for ant control

Store food in ant-proof containers. Denying ants easy access to stored foods is an essential part of ant control. Foods are safe in the refrigerator as long as the seal is sound. You can also use containers with snap-on lids and tight seals or glass jars with rubber gaskets and clamps. In big box stores, whole aisles are dedicated to such containers. You should be able to find them in all shapes and sizes for your various needs. Storing sweets in ant-proof containers is of particular importance, but ants will eat anything.

Clean obsessively in the kitchen and dining areas. Whether you’re dealing with pavement ants, little black ants, Argentine ants, thief ants, pharaoh ants, or any of the other common invasive species, you’ll need to keep a clean kitchen to gain control. Frequently clean all kitchen surfaces to remove food residue as well as ant pheromones. Immediately wipe up spills; don’t assume your dog will take care of it later (a custom in my house, but my dog is reliable). Vacuum daily to remove crumbs and small food particles. Do the dishes promptly after meals and wipe down the sink to get rid of moisture. Also clean drains with baking soda, vinegar, and boiling water regularly to remove ant-attracting filth.

About your garbage can… Routinely clean your indoor trash receptacles to keep any ant-attractants away, and bring the trash outside on a daily basis. Keeping organic garbage (table scraps, anything edible) in a separate, sealable container is a strongly recommended preventative measure for ant control and indeed all pest control. Plastic buckets with snap-on lids (any paint or hardware store) are a good option. You could also compost your organic waste, which is a green, gardener-friendly alternative.

Rinse food containers before disposal. It’s hard to convince people to wash garbage, but I’ll try anyhow. The residue left on glass, metal, and plastic food containers attract ants. You see, that little drop of warm grape soda, while not worth tilting your head back for, is a bountiful find for hungry ants. Similarly, meat wrapping should also be rinsed before tossing, as these attract the more protein-hungry ants (thief ant, Argentine ant, big-headed ant…).

Pet food. Sassy, your overweight spaniel, doesn’t need her food dish out at all hours of the day. Feed her and then remove her food and water bowls. If this doesn’t work for her, surround her dishes in a moat using a shallow tray and soapy water. If she drinks the soapy water, sterilize your animal to protect the integrity of the breed.

Get rid of excess moisture. Ants need moisture to keep an indoor nest growing. Be sure to insulate pipes and fix any leaks.

Habitat Control: Landscaping for ant control

Make your property unfriendly to ant colonies. You’re going to have ants outside. You should – they perform some vital services in your name. However, there are some things you can do to keep ants (and other pests) from growing too numerous or trespassing in your home.

• Get rid of leaf litter and excess vegetation around your home, which provide the protection and moisture that can lead to large ant populations.
• Keep woodpiles, rock piles, pavers, and other clutter away from your home.
• Pests of all kinds benefit from heavy mulch. Mulch is also ugly and unimaginative. Do away with it.
• Work to get rid of garden pests like aphids and scales. These pests produce honeydew, which is fine cuisine to many ant species.
• Trim away tree branches and shrubs that brush up against your home. Don’t make it easy for these six-legged villains.

Physical Controls: Control ants with barriers

When ants are on the march, get in line. Many invasive species will march in lines on their way between their nest and food sources. Don’t make the unforgivable mistake of killing marching or swarming ants without first following them. Watch the ants. See what they are after and, more importantly, where they go afterwards. In this way you will find (A) how they are getting into your home and where their nest is located or (B) where they are nesting inside your home.

The time you take to locate ant nests and entry points will pay off greatly, allowing you to focus your exclusion efforts and chemical treatments in the right areas. Whether you’re following ants indoors or outdoors, focus on cracks and crevices made by baseboards, the tack strip at the edges of carpeting, where siding meets foundation, and where foundation meets earth. Nests are sometimes marked by anthills, but you’ll also find them under gravel, rocks, mulch, pavement cracks and where pavement meets grass, flower pots, and even directly adjacent to the foundation.

If the ants are coming inside from an outdoor nest, seal off their entrances into your home using a caulk and a caulking gun (petroleum jelly or duct tape will work as a temporary fix). Walk around your home both inside and outdoors – look for other cracks and crevices the ants may be using to get inside and apply sealant. Pay particular attention to where utility wires and pipes enter the home as well as window and door frames. Besides caulking gaps in doors and windows, you can apply weather stripping and door sweeps. Repair window screens using silicone caulk or screen patches. If you find that ants are nesting in your cabinet or in a wall void, you’ll want to set out ant baits (see Biological and Chemical Controls). You could also apply an insecticidal spray or dust to their exit/entry points (see Chemical Control) before sealing the ants inside. If you simply must kill marauding ants, wipe them up using a sponge soaked with detergent and water. This will kill the ants and erase the pheromone trail they use as a highway to food sources.

Sticky barriers are effective for both indoor and outdoor ant control. Sticky barriers can be applied around plants, trees, raised gardens, and even the legs of furniture. Tanglefoot makes a variety of sticky barrier products. Sticky Stuff is another good, versatile option. BugBarrier Tree Band is a popular product for ant-infested trees. In a pinch, applying a slathering of petroleum jelly (works well at the base of plants in gardens) will also work as an ant barrier.

Get medieval with moats. When under siege by ants, you can protect potted plants, pet food dishes, and other items by placing them in a shallow pan filled with water and a splash of detergent. The detergent reduces the water’s surface tension so the ants cannot pull a Jesus and walk across. Instead they will drown or become sport for your moat’s small-yet-vicious imaginary alligators. Can you hear the ants screaming?

Mechanical control: Flood the ants away from your property

Ant control with a garden hose. Outdoor ant colonies large and small can be convinced to move out or at least a little farther away by flooding. Cold water from the garden hose will suffice. Reciting verses from the Old Testament can add flair to the event. Ants are stubborn – repeated flooding is usually necessary. Large mounds or deep nests – like those created by fire ants and leaf cutting ants – will need considerably more water to reach the entirety of the ant complex.

A more serious, ant-killing drench. If you want to kill ants rather than just move them, you’ll need to flood their nests with more than just cold water. Pouring a few gallons of boiling water will burn the ants out and collapse their nest. You can also use chemicals. Mixing water with citrus oils (Orange Guard is labeled for this - see Biological Control), an insecticidal soap, or vinegar (plain white) will make for an excellent ant killer. Another option is diluting pyrethroid insecticides like Spectracide Triazicide or Bayer Advanced Lawn & Garden Multi-Insect Killer to make an ant-killing drench.

Biological Control: Natural ant control with boric acid, DE, and more

Make your own boric acid bait to kill ant colonies. Ant baits are the cornerstone of all ant control. Instead of spraying poisons everywhere, which can split colonies up and potentially make ant control more difficult, you bring the ant to the poison. The worker/foraging ants then take the poison back to the nest to share with larvae and queen. This is how colonies die, or are reduced to acceptable levels. Boric acid is a perfect ant poison. It’s cheap, natural, and much less dangerous (though not harmless) than commercial poisons. Best of all, when mixed correctly, boric acid is a slow ant killer – it allows ants time to bring it back to the nest in sufficient quantities for an ant apocalypse. Here are a few boric acid ant bait recipes:

1. Mix three cups of water with one cup sugar and four teaspoons of boric acid (Borax). Pour around a cup of solution into separate jars. Pack the jars with cotton balls to about the halfway point. Seal the lid and poke a few holes at the center. Make a fun skull-and crossbones label and set the jars out in ant trails and hotspots.
2. Some ants prefer protein and grease over sugar (little black ants, thief ants, pavement ants, big headed ants…). Replace the sugar in the above recipe with canned pet food. Or try this recipe: Mix four tablespoons of peanut butter with six tablespoons of honey and one teaspoon Borax.
3. Ok, if you don’t want to make your own boric acid ant baits, there are many boric acid-based commercial products. For sugar-hungry ants, I recommend Terro Ant Killer Ant Baits, which come in both indoor and outdoor models. For protein-hungry ants, try Drax Ant Kill PF.

Use diatomaceous earth – the slow ant killer. Most ant species are susceptible to diatomaceous earth, a desiccant dust consisting of the fossilized shells of ancient algae. These shells are covered in microscopic shards which create cuts in the cuticle of crawling insects. The ants walk over the DE, start leaking, dehydrate, and die. You can apply DE as an ant barrier around the outside of your home or inside, around the perimeter of rooms and carpets (be sure it’s food grade). You can mix DE in water to make a paste to apply to trees. You can get proactive and dust nearby anthills. Using a duster, you can apply DE to the cracks, crevices, and wall voids, where it will remain effective forever.

DE is also great for vegetable gardens. Place one cup of DE in a paper bag. Poke a few holes in the bottom, and then, holding the bag over your plants, beat the bag with a stick. This will create a light dusting, which is most effective (ants and other insects will crawl around large piles, much as you would a large snow bank). Concern and MotherEarth D are two cheap, widely available brands from online vendors.

Capsaicin – a natural ant repellent. Chili pepper, black pepper, red pepper, ginger, and paprika all contain capsaicin and so can be used to repel ants. I’ve heard of people using it as a barrier around homes, but it is best used in gardens. You can apply these powders around the base of plants or in wide bands (5-6 inches) between rows.

Citrus oils kill ants. Linalool and d-limonene - citrus peel extracts found in products like Orange Guard, Citra-Solve, Bugs’R’Done and Pro-Citra DL Aerosol – can be used for ant control in a variety of ways. They can be used as a direct kill spray, a repellent in gardens, as a drench for anthills and outdoor nests, or for treatment of cracks and crevices where ants are nesting indoors (may stain).

Chemical Control: Ant control baits and other ant killers

Ant baits provide practical ant control for home owners. Ant baits come in many varieties, and some will work better than others for different species of ants. I prefer Terro brand ant baits, which use a sweet bait and boric acid and can be used both indoors and outdoors. Other effective ant bait stations include Maxforce FC Ant Bait Stations, Advion Ant Bait Arenas, Advance Dual Choice Ant Bait Stations and Combat Ant Control Bait. To control ants outdoors in large areas, granular ant baits are more practical (though some are labeled for both indoor and outdoor use). These can be applied to lawns using a fertilizer spreader, and they can also be applied around the foundation as a barrier. Advance Select Granular Ant Bait and Maxforce Ant Bait Granular are good examples. Here are some tips for using ant baits:

• Good sanitation practices (see Behavioral Control) will make ant baits more effective. Hungry ants can’t be choosy.
• Don’t use sprays or dusts near bait. Ants can’t bring the goods back to the queen and her minions if they’re dead, can they?
• With ant baits, more is better.
• If you’ve used bait according to the label and have given it time to work but have not seen results, switch baits.
• Read all labels and warning carefully. The ants win if you poison yourself, your children, or your pets.

Use ant-killing sprays and dusts in focused areas. Generally, the ant insecticides you find at hardware and garden stores will do what they say they do – kill ants. However, more important than the product you use is how you use it. Killing individuals on the prowl will have little to no effect on an ant colony. You want to focus your efforts where the ants are nesting; this is where your ant reconnaissance comes in handy (see Physical Control).

If you follow the ants and see that they are nesting indoors, you can apply ant-killing aerosols like CB-80 Extra, D-Force HPX, or Microcare Aerosol to cracks, crevices, and wall voids. Or, you can apply an insecticidal dust like Delta Dust Insecticide, EcoExempt D, or Borid Boric Acid Dust to said cracks and crevices before sealing them off with silicone caulk.

If ants have become a serious problem outdoors, you may want to invest in a sprayer and a suitable ant-killing spray. Suspend SC Insecticide, Demon WP, and Demand CS are all good options.