Who doesn't hate walking in their kitchen and seeing a long trail of ants coming down the wall and amassing in a large group on the trash can? These persistent little critters can be difficult to deal with, but the situation is not hopeless. You can get them out of your kitchen without using toxic chemicals!
I had tons of ant problems in our 1890's Edwardian when we first moved in. San Francisco is basically one big ant colony - Argentine ants arrived on a cargo ship at some point and turned the entire city into a giant anthill. After much trial and error, I figured out how to combat the problem by observing their behavior. I'd start out by scrubbing their scent trails with vinegar by beginning at the end of their trail and following it back to the source, vigorously scrubbing the whole way so new ants couldn't follow the now-dead ones back into the house. Once I found their entry holes, I filled them with Borax or diatomaceous earth and sealed them off with clear caulk, making Evil Mad Scientist voices while I did it. "MUA-HA-HA-HA!" It helped, along with going around inside and outside the house, finding their entryways and blocking them off with more Borax/diatomaceous earth and clear caulk.
Another way to impede the progression of ants is to get them to take poison back into their homes and feed it to the queen and the other ants in the colony. I made my own ant bait by dissolving ¼ cup honey with ¼ cup sugar in a heat-resistant glass jar in the microwave on high for one minute. After the sugars had dissolved, I added ¼ cup borax to this, stirring well. Then I went outside and placed a tablespoon of this mixture in the ant pathways and on the anthills. Ants are attracted to sugar, and since honey is sticky, it holds the borax and keeps it from blowing away in the wind. If it rains, be sure to reapply - borax loses its effectiveness if it gets wet. Ants think borax is food, but it's very toxic to them and they die after eating it.
You also have to be extremely vigilant about keeping your house and kitchen clean! Preventive measures include wiping down the counters, keeping the floors clean, not leaving food out, and keeping sugary foods well-sealed. Seal dry pet food in airtight containers.
Some people swear that sprinkling powdered cinnamon around the house and around the edges of the floors works, but I found it to be labor-intensive and expensive - you need a lot of cinnamon for this, and you have to reapply when it rains, when the wind blows, or when you vacuum. Also, the cinnamon blows around and makes a mess. I found the same issues with peppermint oil - it's costly and time-consuming, and I got tired of my house smelling like a candy cane. Clear caulk is really the way to go, you just apply it once and it's not going anywhere because it's waterproof, it doesn't fade or blow away, and the ants are simply just not going to get past it.
I haven't seen ants in years ... uh oh, I hope I am not jinxing myself now. *knocks wood*
Related:
Tips: Bay Leaves in the Pantry
Mice In the Kitchen! How Have You Dealt With Mice?
(Image: Flickr member justin licensed for use under Creative Commons)
posted originally from: TheKitchn

Stanley Console by ...
So is borax safe with cats?
And does anyone know how to keep ants out of petfood bowls?
Thx!
What about roaches? Summer's coming up, and they like the heat, especially in apartment buildings with filthy neighbors...
Gexx, I put my cat food bowls on a plate that is covered in cinnamon. The ants won't cross the cinnamon to get to the food.
I don't use borax in my house because of my cats and bunnies. I have heard that diatomaceous earth is safe around cats though.
I usually find where the ants are coming into the house and blanket the area with cinnamon or cayenne. That seems to discourage them and they move on to someplace else (another apartment, I presume).
I lived in a place once that had an ant problem. I put the dog bowl inside of a tin pie plate and put a little water in the bottom of the pie plate. (Put this all on easy to wash dish towel or mat due to possible water mess.) I also had to repack cereal and such in gallon baggies...then put them back in the pantry.
Treating the outside with those little stick pesticides things you can buy is much better than spraying the inside if you have pets or children.
I read online that ants could not get through baby powder so put it anywhere in the kitchen I thought that they could be coming in from. Still an ant would appear.
I then decided to say f'k it and use bug spray between the screen and window sill and at the base of the cupboard under the sink. Still ants appear. All but 3 have been in the kitchen.
I have yet to find their nest or pathway or ant hill (I'm on the 3rd floor). It is driving me crazy.
Oh and these are ants that fly. I never knew that kind existed until I moved to TX recently. Ugh.
I moved to the mountains and now have the huge black ants...and boy do the pack a bite! They also get the kids in a tizzy. I rememeber buying clove powder when I lived in a big city and it would spray a light coating easily. I also remember reading that they wont cross chalk lines but recall this never worked with argentine ants.
Out of desperation, I took some talcum powder (baby powder) i dont even use and mixed a very small amount of ground cloves in it. Since they are invading our add on bath room i put it on a butter knife and dropped it in the gap at top of baseboard moulding and any openings around the floor boards. The big ants are quite illusive and my house is too old to fill holes. The ants still inside wouldnt cross the powder and the clove scent made them nuts. Im hopeful and the remedy was cheap and safe!
Peppermint oil is a neurotoxin for ants- I only used it to kill the existing ants, and then TERRO traps for a long(er) term solution. I liked the peppermint oil because it would paralyze the ants instantly (and I bought it from ACE in an easy to apply spray can- can't remember the brand- the can was yellow though), and I could spray to my hearts content in the kitchen without worry. The spray didn't deter them later (that's what the TERRO traps were for), and I now resent anything that smells like peppermint, but it was super effective for killing them INSTANTLY! (I also had the evil laugh.)