Most New Yorkers who call us have already tried a hardware-store spray. It seemed to work for a few days. Then the ants came back — sometimes in larger numbers.
Pavement ant nests extend two to three feet below the surface. A spray dissipates long before it reaches the queen’s gallery. What it does reach are the foragers — the workers you can see. The colony simply produces more to replace them. Worse, repellent sprays contaminate the area around bait stations, preventing ants from taking the bait. If you sprayed and then put out a store-bought bait station, the ants likely avoided the bait entirely.
Professional-grade baiting works on a completely different principle. Slow-kill bait is placed along active foraging trails. Workers carry it back through the colony’s tunnels, sharing it with other workers, the brood, and eventually the queen through a process called trophallaxis — essentially, food sharing. The delayed kill, which takes three to five days to show visible results, is what makes the treatment effective. It gives the bait time to move through the entire colony before the workers die.