They’re a nuisance, but you don’t need harsh chemicals sprays to control these household pests.
The easiest way to reduce the chances of small unwanted pests is by wiping or sweeping up spilled edibles in the house immediately, storing food and compost scraps in secure containers, putting dirty dishes in the dishwasher right away, rinsing out recyclables, and emptying the kitchen garbage frequently. This is good advice for the control of many pest problems and makes your kitchen a nicer place to hang out in, too.
If you are seeing a trail of marching ants in your house, follow it away from the food as they leave your house to find the general area of their nest. Then seal up whatever tiny crevice their colony is using to get into your house. Low VOC water proof silicone caulk is a good and long-lasting option. If the bugs are strolling boldly in and out under a door, sealing the gap with a door “sweep” will work to rid them from your house, but won’t kill them. A door sweep is a flexible device that blocks the space between the bottom of the door and the ground while still allowing you to open and close it. Some models install with an adhesive strip or simply snap onto the bottom edge of the door—so installation is quick and easy. Sealing cracks and holes also cuts down on air movement, saving you money on your energy bills.
It can be difficult to find and control every tiny entry point to your house. But even if ants haven’t found a way in yet, it never hurts to have a good defensive strategy in place. You can buy safe, commercial ant repellants such as EarthKind’s Stay Away Ant Granules. Or you can just grab something you already have on hand that ants aren’t fond of. Lemon juice works, as do lemon and orange oil, or dried crushed citrus peel, ground cinnamon, cinnamon oil, dried peppermint leaves, peppermint essential oil, peppermint castile soap, cayenne pepper, dried coffee grounds, whole garlic cloves, powder dried garlic, dried lavender, lavender oil, or chili powder. Once more, these will not kill the pests, but they will prevent you from having a bad ant infestation.
For best results, sprinkle or spray the solution of your choice in areas ants tend to go. Bugs also don’t like the feel of food-grade diatomaceous earth (DE), powdered chalk, or talc (baby powder). Use one of those to draw a line across a known opening (they work only in dry locations, do not mix with water), and you can be pretty sure no ants will cross it.
If the other methods have failed to rid your house of an ant problem, you may want to try putting a boric acid-based bait to work, which will kill an entire nest over the course of a few days (or weeks) time, as the foraging worker ants carry it back for all the colony members to eat. Boric acid kills ants but is relatively nontoxic to humans and pets in small quantities. There are many commercial brands, but it’s easy to make ant bait from boric acid powder or borax.
If your ants are attracted to foods full of sugar, mix the borax or boric acid with sugar water or honey, and serve it up in a recycled can bait station. If you’re dealing with ants that seem to be drawn to protein-rich or fatty foods, attract them with a blend of borax or boric acid with peanut butter and sugar. Keep refilling your dispenser until you no longer see any coming by or until the bait no longer disappears.