When an ant eats a grit, the grit expands when it hits the water in their digestive tract. This expansion kills the ant. (They literally explode, but you probably didn’t need to know that.)Leave a small pile of grits where the ants are coming in the house. They’ll eat some and take some back to the nest where others will eat it and die. If you’re leaving grits outside, make sure it’s not supposed to rain or dew heavily. Once the grits are wet, they’re already expanded and the killing property is gone. Grits are also effective on fire ants and other kinds of ants.
Cornmeal works the same way as grits.
Oatmeal works the same way as grits.
Vinegar won’t kill ants, but it will erase the chemical trail that the ants leave behind for others to follow. When you see a trail of ants, go behind them and wipe down the surface with vinegar. Any coming in after you do this will have a hard time finding the trail.
This is the most obvious solution. Find whatever the ants are after and clean it up, seal the bag or box, or get rid of it. Sometimes they’ll come in and there will be no obvious attractant to be found, but if you can find what they’re after, you can deter them.
The easiest way for me to clean up an ant trail is with the vacuum cleaner. I suck them up and then erase the trail with vinegar. You can either empty the bag/canister immediately or you can place a small piece of a flea collar in the bag or cup to kill the ants. This is also a frugal way to control fleas if you have pets.
Lemon juice, like vinegar, is a trail eraser (and it smells nicer than vinegar).
Remove The Easy Access
If you have trees or shrubs that touch your house, trim them back. The ants can easily get to your house from the branches. This is especially important if the tree/shrub makes sap or nectar that will attract the ants. They seem to figure, “Hey, we’re already here, let’s just take the short trip across this branch to see what’s in the house.”
This won’t kill ants, but ants will avoid cinnamon. You can lay down a cinnamon barrier at their entry point and they won’t cross it.
Diatomaceous Earth (DME)
This powder, derived from a naturally occurring rock, will dehydrate and kill an ant that walks through it. Lay down a DME barrier at their entry point. In small amounts, DME is safe for use around pets and children. Do not use in wet environments as this will deactivate the killing property.
Ants are a pain, but as insects go most of them are harmless. You’ll probably do best to employ at least two of these methods to quickly solve your ant problem. For example, I set out grits to be sure that the nest is killed and I also use a barrier method like DME or cinnamon. If I see a trail, I’ll also use a trail eraser and the vacuum cleaner. The more methods you employ, the faster the ants will either die or give up. The good news is that you can control ants safely and effectively without resorting to expensive, toxic sprays and bug bombs.
(Photo courtesy of Lindspetrol)