This is another one of my "I didn't invent this or even dream it up myself but it works so well I had to give my personal testimonial" posts. Last month when it started raining (April showers, you know) I was overrun by little black ants. They were in every bathroom and the kitchen. EWWWW! It's just so gross to see ants all over the kitchen. It makes you feel like your house is a disgustingly dirty haven for bugs, which isn't true but that's how I felt. And something about being naked the shower and seeing ants crawling up the walls made me want to move into a hotel.
This happened to us when we lived in California and I bought something called Terro, which worked very well but it was pretty expensive. I didn't want to spend $30 on ant killer for all the areas in my house that needed it.
So after scouring Pinterest and finding several posts about this method, I tried it. It worked like a charm! Then I tackled the outside of the house. Bingo - no more ants!
CHEAP AND EASY WAY TO GET RID OF ANTS
Plastic wrap or aluminum foil
A few containers, like mason jars
STEP ONE - Inside the house
Mix one cup of sugar in 1/2 cup of hot water. Mix until the sugar dissolves and it makes a thick simple syrup.
Now add 1 tbsp of Borax (found in the laundry aisle. It comes in a box and it's a white powder.)
Soak cotton balls in the mixture and place wherever you see the ants. I put them on the bathroom floor, the corners of the bathtubs, and on the windowsill over my kitchen sink. Place a small sheet of plastic wrap, silver foil, or a flat dish of some sort under the cotton balls. Here it is in my powder room at the base of the sink.
A few ants will discover it and say, "OMG! There's sugar all over the place in here! Quick, run back to the nest and tell everybody else!" Within hours your cotton balls will be swarming with ants. It's horrifying, yet weirdly mesmerizing. Like a train wreck, you can't look away. Click on the photo below for a really gross close up. They're like little piggies at a trough, all lined up around the edge drinking the sugar water. I tried not using cotton balls for this area since the plastic lid I used as a plate had that little moat around the edge, for lack of a better word. It worked just fine since it wasn't a deep bowl.
The ants eat the mixture and go back to the nest and die. Replace the cotton balls after a couple of days when they dry out. A new crop of ants will show up. They will all bite the dust too. This took about a week for me. Tons of ants the first few days, then a few stragglers, then another group for round two, and by day seven they were gone. GONE, I TELL YOU. I have not had to repeat this and it's been several weeks now.
STEP TWO - Outside the house
Mix sugar and borax 50/50 and sprinkle around your house's foundation, plus anywhere you see ants. For me it was at the garage door, along the sidewalk, the post of the mailbox, and below all the bathroom and kitchen windows. Within a few days I saw no more ants. Period.
IS BORAX SAFE AROUND KIDS AND DOGS?
From what I have read, Borax is only dangerous if ingested in very high quantities. To an ant, 1 tbsp is a very high quantity. But to a dog or even a child, it may cause stomach upset or nausea but nothing dangerous. Having said that, don't leave the mixtures around where your toddler can get to it and you might want to treat and close off one bathroom at a time so that kids aren't tempted to put the cotton balls in their mouths. I did all the bathrooms except for one on the first go around. I closed them off to keep the kids out of there. Then when those were clear of ants I did the final bathroom.
Now I know what to do next spring! I have no idea if this works with fire ants of carpenter ants, but for the little black sugar ants it was 100% effective.
Good luck, ant slayers!