[patriofarmer]

Found this a while ago, never had any issues with them myself.

Most of the common pest ants, though, have a few traits in general that make it much easier to control them.
For instance, all three kinds of ants mentioned have a distinct liking for things that are sweet. This leads to a couple fairly easy methods for killing them.
One of the easiest ways is to mix baker's yeast with molasses in a bottle cap and to place it where the ants can get to it. It should be put where pets cannot get to it, however.
The yeast and the sugars in the molasses combine and begin to ferment. However, the reaction is slow because of the properties of molasses. The ants ingest this and take it back to the hive or hill. Invariably, it ends up being fed to the queen.
Here's the thing, though. Fermentation of sugar results in the creation and expulsion of carbon dioxide. This is what makes bread rise, and it is what makes you burp when you drink beer or pop too quickly. Ants can't burp. So the buildup of the carbon dioxide kills them, and if the queen is killed, the nest dies. (Unlike bees, ants can't just feed special food to larvae to produce new queens.)
The second method may be surprising to some people. In involves artificial sweeteners like the trademarked Sweet 'n Low, and it works especially well with carpenter ants. Perhaps the most surprising fact for many people, especially those who use it, is that this product line was originally developed as an ant poison. Restaurants and store currently make it available for human consumption, but it really is deadly to ants. (It probably doesn't do people a lot of good, either.)
Note: Many people dispute that artificial sweeteners will kill ants or that they were ever used for that purpose. However, many who have tried this method were met with total success. If it works, it works.
With artificial sweeteners like this, spread the powder along ant trails, where the ants can find it. There is no need to worry about pets, since they usually won't touch the stuff. Again, the ants will take the sweet tasting powder back to their nests and feed it to the queen. Death takes longer than with the yeast mixture, but it does occur.
Once the queen is dead, the colony can no longer survive, and it will die out. Both of the methods mentioned above have been used by the author, and have worked remarkably well. The latter method was used to eradicate a very large and well-established carpenter ant nest that was living in the walls of the house and burrowing in the wood. The former was used to remove a nest of fire ants. In both cases, the ants died out and were never a problem again.
Killing ants isn't a trick. Many things will kill them, including commercial sprays. However if you want to kill a nest, you must get to the queen. The above methods allow you to kill the queen, and thus destroy the entire nest.