May 19, 2013 - 08:36 PM
I just looked at the most recent Fire Ant Distribution map for the US, and it doesn't show Fire Ants in Chicago. It is possible that Fire Ants have made it up that far, but it is also possible that your menace ant is pavement ants. What you are describing is very common in the Southern states - especially for Fire Ants.
The good news, is that either of these ants are fairly easy to control once they get indoors. What happens, is that in the winter, these ants go underground usually below the frost line to overwinter. They also have to continue foraging for food and moisture.
Plumbing lines that lead into the home can sweat, leak, etc, and this is a huge attraction for ants. Toilets especially, because they sit on a wax seal, and there can be some seapage, moisture etc, that can attract the ants.
Here is how it is done - Mix Termidor SC in a sprayer at a rate of .8 oz per gallon of water, and spray the entire foundation 1 foot up and 1 foot out. Completely saturate the soil next to the foundation. This could take up to 2 gallons of mix.
Go under the house, and do a very careful inspection, look for ant mounds that are resting against the interior foundation and any mounds that are resting against plumbing lines, piers, etc. If you find any mounds under the house, completely saturate the mounds with Termidor SC. Mix the Termidor again at a rate of .8 oz per gallon of water in a small bucket. Completely saturate the ant mound until wet.
Termidor foam is applied by injecting directly into the wall voids where the ants are active. Either pull the silver rings back where the sink lines go into the wall (under sink cabinets), and inject into the wall this way, or take a nail or a small drill bit and make a small hole about 1 inch above the baseboard and inject Termidor SC into the wall for about 10 seconds. Do this in between each stud along the entire length of wall if possible.
The Toilet hopefully has some space between it and the floor where you can inject Termidor foam under the toilet flange. Inject as much as you can and wipe up any spillage. If there is no space and you cannot inject any foam, then the toilet has to be removed and the cracks around the toilet drain line can be foamed. If you remove the toilet, be sure to replace the wax seal.
There are other methods to control these ants, but this is the best, sure - fire way to control them. Once you do this, your ants problems indoors will be solved for many years.