Ant Control in Baltimore, MD

Why do ants keep coming back after I spray?

Spraying kills the workers you see but leaves the colony intact, and repellent sprays can scatter workers and split a colony into several. Ants also leave scent trails that new workers follow. Baiting, which workers carry back to the nest, plus sealing entry points, works better than contact sprays for most trailing ants.

Wiping a trail with a household cleaner can remove the scent line, but the ants simply lay another. If you plan to bait, avoid spraying near the trail and avoid cleaners that leave a strong smell, because the ants may then avoid the bait.

Honest expectations help here. Bait can take days to weeks to reduce a colony, and a short rise in activity at the start is normal.

Which ants are most common in Baltimore homes?

Odorous house ants and other small trailing ants are common indoor visitors, and pavement ants, larger carpenter ants and others turn up around foundations and in wood. The exact mix varies by block and season. A technician identifies the species because each responds to different baits and treatments.

Odorous house ants often nest in wall voids, under siding and in damp areas, and they love sweets. Pavement ants nest in soil and pavement cracks and are often seen along walkways and brick. Carpenter ants have their own service page: see carpenter ant control.

Do not be alarmed by a single ant. Several ants in the same place, day after day, mean a trail and a nearby colony.

When is ant season in Baltimore?

Ant activity commonly begins in spring as temperatures rise and peaks in the warm, humid months, with some ants moving indoors during heat or heavy rain. Cold weather slows outdoor ants, but colonies inside heated walls can stay active. Exact timing varies from year to year with the weather.

March and April often bring the first foraging ants, and by May and June trails are heavy as colonies grow. In July and August, hot weather and storms can push ants toward kitchens and bathrooms for water. See our Baltimore pest calendar for the full year.

How do I stop ants from getting into a rowhouse?

Seal gaps where pipes and wires enter, repair cracked caulk around windows and doors, fix leaks, keep food in sealed containers and take out trash promptly. In attached houses, ants can also travel through shared walls and rooflines, so talk with a neighbour who has the same problem.

Brick, mortar joints and old window frames provide tiny gaps. A thorough rowhouse pest proofing job looks at those joints as well as the obvious holes.

What should I do while ant bait is working?

Leave the bait in place, do not wipe the trail or spray repellents nearby, keep other food sources sealed and give it several days. Activity may rise at first as workers feed and carry bait back to the nest. If ants are still strong after the time the technician suggested, call for a follow-up.

Wipe up crumbs and spills away from the bait, but not on the trail itself. Put pet food in a sealed container or lift the bowl between meals. Move sweet items, such as honey, syrup and fruit, into the refrigerator for a few weeks while the colony takes the bait.

Resist the urge to kill the ants you see. They are the delivery service, and each one that reaches the nest takes the bait with it. If you find a second trail a few feet away, tell the technician; colonies can have more than one nest and more than one route.