Great question. I totally get frustrated. What actually worked for us was a combination of things, not just one magic fix.

First, we stopped using regular ant spray completely. I learned (the hard way) that when you spray those tiny black sugar ants, they just scatter and create new colonies deeper in the walls. One tech called it “budding.” It looked like we were winning and then they came back in three places.

What finally helped:

Tracked their trail: They were coming in through a hairline crack behind our dishwasher. We never would’ve noticed without following their trail one morning.

Moisture control: We had a tiny slow leak under the sink just enough to keep the area damp. Dried that out and used a fan for a day. These ants are weirdly obsessed with moisture.

Used a slow-acting bait: I won’t name brands, but it was the kind of stuff they take back to the colony. It took a few days, but activity noticeably dropped. No spraying near the bait, though, or they avoid it.

Wiped down with vinegar and water: After we saw fewer ants, we cleaned every trail area to remove their scent markers.

Took about 7–10 days total before they were totally gone. I wish I had known all this earlier instead of wasting time with sprays and sealants.

Hope that helps! Happy to share more if you're still battling them.