I garden organically and here is how to keep anything out of anywhere - in this case banishing ants from a home or garden. It will take some preparation, but I guarantee it will work!
This plan has two general parts - area deterrence and offense against the nest. The goal is to drive them from where they are not wanted and hopefully redirect them to a safer area where they can live in peace - ideally with minimal ant casualties (no poison, all organic).
Part 1 - Soapy Hot Pepper Spray:
Find the biggest old pot you have and fill it with coarsely chopped super hot (at least habenero) peppers, up to one pound (450g), seeds still in, and pour a gallon of white vinegar over the mix - simmer this with the lid on the pot (with all windows open or outside) for an hour or for as long as you can bear it. Add water or more vinegar as needed to keep the pepper sauce thin enough to easily pour and stir gently as needed - we do not want a paste, so keep the mix fairly wet.
Fill a five gallon bucket with 2 cups of dish washing liquid and fill with about 3.5 gallons of hot tap water - be careful not to cause suds, as much as possible.
If you like spicy foods, save a cup of your pepper sauce - it makes great hot sauce (add sea salt) ! Pour the rest into the 3.5 gallons of hot soapy water, stir gently, cover the bucket and let sit for 24 hours or more, the longer the better.
Part 2 - Redirect the Ants:
You can get a lifetime supply of Diatomaceous Earth (DE) from Amazon for about $50, but if you find a farmer supply shop it is less than half that price - farmers use DE all the time to deworm livestock. It is completely safe, even beneficial, so no worry at all if you find your pets eating it - but insects hate the stuff. It is like little razor blades that they cannot get past.
Find the Nest:
While waiting for your hot pepper spray to marinate, find the ant nest. Do this by laying out corn meal (not instant grits but raw corn meal) where you see them, they should pick up the corn meal and start heading back toward their nest.
Worker ants cannot eat hard foods so they take it back to their nest to be digested, but corn meal is too hard to digest so it messes up the internal rythym of their nest (so you don't have to worry that you are feeding them). The returning ants will lay a scent trail telling others that there is food at your corn meal pile, so the ants should stop hunting and start concentrating on this pile of free food, keep feeding them corn meal while you wait for your pepper spray and Diatomaceous Earth - if you are waiting for a DE delivery, you can slowly move the pile outdoors day by day and the ants should follow. When our real assault starts this group of ants should give you a great test site to see just how much they hate the pepper spray. The more corn meal they take back , the worse off they will be later, and the more likely they will move nests when you start the pepper attack.
Preparation for the Offensive :
Once your pepper spray is ready, lay a long line of Diatomaceous Earth across the outside of the entire section of your house facing the ant's nest and a second line of DE half surrounding the ant nest, so as to drive them away from your home and out toward safety. The line should be about the width of your middle finger, very dense in the center with about a half hands width of sprinkling on either side as extra deterrence. Surround your home and the nest as shown in the image.
This line is fairly impenetrable to ants and you can consider it your heavy guns, it will take a few weeks before it becomes ineffective, and by then the ants should have moved on.
Now place a pile of corn meal in the direction you would like the ants to head (see image)
Attack! :
Your soapy pepper spray should have been marinating for a while now - strain it through an old tee shirt and into another 5 gallon bucket - or, strain just enough for a couple day attack (about a gallon) an let the rest continue to soak. This should leave you with a sprayable soapy pepper mix, fill a spray bottle with the mix and let's get started on offense.
The best offense is a good defense, so first let's reinforce our Diatomaceous Earth line with pepper spray so that any tough ants who get past the DE run into a pepper spray line. Don't use too much here, because it will wash away from the surface quickly, but just an extra kick for those ants who find a way through the DE. Use the stream setting of the sprayer, not spray, and trace the DE line as shown in the pic.
Now for the attack - take a large stick and shove it straight down into the center of the opening of the ants nest and pour a five gallon bucket of water right into the ants nest. Let that soak in for a few minutes. Once the water has soaked into the nest, stream spray the nest with a good half gallon of the pepper spray, this will let the spray really soak into the soil and get great penetration. Sprinkle a handful of DE down into the hole. Do this daily for a week.
At the end of this week the ants will not know what hit them. The DE line around your house will keep them out, the line around their nest will keep them from flanking you, the cornmeal will mess up their food supply chain, the bait corn meal will redirect them out into a safe space, and the pepper spray will make their nest uninhabitable. Sometimes a new opening into the nest will open, but they can only do this once or twice. Hit that opening with a days or two of pepper spray and they should get the hint.
There you have it. An organic attack on even a years old ant nest. The pepper spray will even keep raccoons out of your garden.
PS - if you want to keep deer out of your garden, use this pepper spray and string 30 lb fishing line around the garden (about belly button height). The deer can't see it so they won't jump over it and it really freaks them out. Not a nibble!
This post was originally a response to a very interesting post from kus-knee It was his idea to repost it as it's own thread. Thanks Kus-Knee!