Bait beats spray. Nearly every ant trail in a Los Angeles kitchen belongs to the Argentine ant, which UC IPM calls the most common ant in and around California homes, and its colonies are built to survive a can of insecticide. The honest answer to how to get rid of ants is slower: seal the entries, take away food and water, set bait on the trail, and wait while the workers carry it home. For stings or winged ants, see ant bites and flying ants in Los Angeles instead.
Why do sprays fail against Argentine ants?
Because a spray only reaches the workers walking through it, and workers are the one thing an Argentine colony replaces easily. UC IPM notes that Argentine ant colonies contain multiple queens, so there is no single queen whose death ends the colony. The nest itself, usually in shallow soil outdoors under mulch, stones, or pavement, never touches the spray.
Argentine ants also do not live in isolated nests. UC IPM describes their colonies linking into one supercolony, with queens and workers moving between nests. Kill today's trail at the baseboard and an adjoining nest supplies tomorrow's. A sprayed kitchen stays clear for a few days, then refills: the colony was never touched, only its commuters.
Why does ant bait work when sprays don't?
Bait turns the colony's habit of sharing food against it. Foraging workers eat the bait or carry it off, then pass it to nestmates, larvae, and queens. A good ant bait is slow-acting on purpose: the forager has to survive long enough to make the delivery. UC IPM recommends baiting over spraying for exactly this reason: it is the only method the workers deliver to the queens for you.
For Argentine ants, sweet baits usually work best. UC IPM notes the species is strongly drawn to sugary foods such as the honeydew produced by aphids and scale insects on landscape plants. Expect the trail to get busier right after baiting. That recruitment is the plan working, not failing.
What brings ants indoors in Los Angeles?
Weather pushes them in, and the kitchen keeps them there. UC IPM lists food, water, and refuge from hot, dry weather or flooding among the reasons ants enter buildings. In an LA summer, a dripping faucet, a damp sponge, or a pet bowl can be the main attraction. In winter, the first soaking rains flood shallow outdoor nests and drive whole colonies inside.
Once they are scouting, three things attract ants most reliably: standing water, sweets, and grease. Fix drips, dry the sink at night, wipe sugary spills, keep trash lidded, and rinse recycling. Outside, trim branches and shrubs that touch the house, since Argentine ants trail along them, and deal with honeydew-producing insects on plants near the foundation.
How do you get rid of ants step by step?
Work in this order, and resist the urge to spray along the way.
- Seal entry points. Caulk cracks around windows, doors, pipe penetrations, and the foundation. If the ants are using one main gap, bait beside it first and seal it after the trail dies out.
- Remove water and food. Leaks, pet bowls, crumbs, open sweets, greasy stovetops. A colony with nothing to haul home has no reason to keep a trail running.
- Place bait directly on the active trail. Set a sweet liquid or gel bait where the ants already walk, out of reach of children and pets, and nowhere you have sprayed.
- Wait days, not minutes. The trail will swell before it shrinks. Refill or replace bait that dries out or empties, in the same spot.
- Wipe stray trails elsewhere. Clean trails in rooms where you are not baiting, as explained below.
Does wiping the trail with vinegar kill the colony?
No. Ants follow a pheromone path their nestmates laid down, and soapy water or diluted vinegar erases that scent trail so the next wave of workers loses the route. It is useful housekeeping, but it kills nothing. The colony, its queens, and its brood are unaffected.
So use it selectively. Wipe trails in rooms where you are not baiting, and wipe the old route after a trail has died out. Never clean the trail that leads to an active bait placement: that trail is the supply line carrying insecticide back to the nest, and erasing it cuts off your own delivery.
What are the most common mistakes?
Most DIY failures come from treating the ants you can see instead of the colony you cannot.
- Spraying on or near the bait. The spray kills the foragers before they deliver anything, and residue can make the ants avoid the bait entirely. Pick one method; for ants, that method is bait.
- Setting off a fogger. A fogger fills the room with droplets that settle on exposed surfaces. It does not reach a colony nesting in a wall void or outside under the slab, so it trades a few dead workers for pesticide on your counters.
- Moving the bait around. Relocating bait every few hours breaks the recruitment. Place it on the trail and leave it.
- Quitting after two days. A multi-queen Argentine colony takes time to collapse. Judge results in weeks, not hours.
Do carpenter ants need a different treatment?
Yes, and the signs are different too. Carpenter ants are among the largest ants you will find in an LA home. UC IPM notes they excavate galleries in wood to nest but do not eat it, and they favor wood softened by moisture or decay: a leaky roofline, a damp window sill, a stump against the fence. Look for coarse, sawdust-like frass pushed out below nest openings, often mixed with insect parts, and expect most activity at night.
Carpenter ant control depends on finding and treating the nest, not on trail baiting alone. UC IPM notes that an indoor nest is usually a satellite of a larger parent nest outside in a tree, woodpile, or landscaping materials, so the inspection has to cover the yard as well as the wall. Correcting the moisture problem that softened the wood is part of the treatment; skip it and the next colony moves into the same spot. Carpenter ants also bite and swarm in spring, both covered in our ant bites and flying ants guide.
When is it time to call a professional?
When the problem outlasts honest DIY. Three situations in particular:
- Recurring invasions. If trails return every few weeks despite sealing, sanitation, and patient baiting, the pressure is coming from the supercolony in the surrounding landscape, not from anything you missed in the kitchen.
- Multiple colonies in the yard. Nests under pavers, in mulch beds, and along irrigation lines re-invade faster than retail bait placements can knock them down.
- Carpenter ants. Structural wood, hidden nests, and a moisture repair belong with a licensed professional.
PesPro identifies the species first, because Argentine ants, carpenter ants, and fire ants each call for a different method, then targets the colony rather than the trail. That is the ant control Los Angeles and San Bernardino County homes rely on when baiting alone cannot keep up. The inspection and the written quote are both free. We are QualityPro accredited, operate under California license PR-6378, and serve both counties from El Monte, in English and Spanish.
Our ant control service comes as a one-time targeted treatment or as part of a bi-monthly or quarterly plan, and every service carries a 30-day guarantee: for ants, a return visit within 30 days costs 30% of the original price. Request a quote or call (323) 472-5329.
Frequently asked questions
How long does ant bait take to work?
Days at minimum, and sometimes more than one placement. The foragers have to find the bait, recruit nestmates, and ferry it back to multiple queens. UC IPM says treatments made in late winter and early spring, when colonies are just beginning to grow, are the most effective.
Should I kill the ants feeding on the bait?
No. Every worker on the bait is a courier, and the dose it carries is meant for the queens and brood, not for the worker itself. Let them load up and walk home. If a thick trail elsewhere in the house bothers you, wipe that one, never the one serving the bait.
Why do the ants come back every year?
Because the supercolony outside never left. Baiting collapses the colonies pressuring your house; it does not erase Argentine ants from the neighborhood. Sealing, moisture control, and keeping plants off the walls lower the pressure between seasons.
Does PesPro treat Argentine ants?
Yes. Argentine ants are the most common species covered by our ant control service, along with carpenter ants, fire ants, and odorous house ants. We treat the colony, not just the ants you see, with methods tailored to each species. The written quote is free. Call (323) 472-5329 or request a quote.