Every June the ants find their way into our kitchen. A thin black line marching from the window sill to the cat food bowl. The first year I sprayed them with Raid. They were back in three days. The second year I tried the natural methods everyone talks about. Some worked. Some absolutely did not.

What Actually Works

Vinegar erases the trail. Ants follow pheromone trails left by scout ants. Wipe the trail with a 50/50 mix of white vinegar and water. This does not kill ants — it erases their map. Without the trail, new ants cannot find the food source.

Wipe the entire path, not just where you see ants. The trail extends further than you think. Go a foot past the last ant you can see in both directions.

Seal the entry point. Find where they are coming in. Usually a tiny crack in the window frame, a gap under the door, or a hole around a pipe. Fill it with silicone caulk. This is the only permanent fix.

Diatomaceous earth at the entry. Food-grade diatomaceous earth is a fine powder that cuts through the ant’s exoskeleton and dehydrates them. Sprinkle a thin line at the entry point after you have sealed most of it. It is not toxic to humans or pets.

What Does Not Work (Despite What the Internet Says)

Cinnamon. Ground cinnamon sprinkled at the entry point does exactly nothing. I tried it. The ants walked right over it. Same with black pepper, coffee grounds, and lemon juice. They might deter ants for about five minutes before the scent dissipates.

Chalk lines. Drawing a chalk line supposedly blocks ants because they will not cross calcium carbonate. The ants in my kitchen did not read that blog post. They walked right across the chalk.

The Bait Strategy

If you have a serious infestation, killing the visible ants is not enough. You need to kill the colony. Borax mixed with sugar water is the classic DIY ant bait. Mix one teaspoon of borax with half a cup of sugar water. Soak cotton balls and place them near the ant trail.

The ants carry the sweet poison back to the colony. It takes two to three days to work. During that time you will see more ants, not fewer, as the bait attracts them. Do not kill them during this phase — let them carry it home.

Keep borax baits away from pets and children. It is low toxicity but not zero toxicity.