PK-A06 · Ants
How to get rid of Argentine ants
Linepithema humile
Argentine ants form enormous supercolonies. In coastal California they replace native ants and then treat your kitchen as one more node. Trail spraying is a joke at that scale. Liquid sugar baits, habitat (less irrigation against the house), and professional baiting programs are the only approaches that dent them. If you live in a Linepithema neighborhood, you are managing pressure, not “eradicating ants from California.” UC IPM has spent years on this species — use that, not a fogger.
How to identify Argentine ant
- Small, uniformly brown, one node, musty odor when crushed (different from coconut Tapinoma).
- Dense trails, often along edges and irrigation lines.
- Shallow nests in mulch and under objects — easily flooded indoors after watering.
Signs of an infestation
- Highways of ants on foundations and into kitchens.
- Sudden indoor invasions after irrigation or rain.
Biology and why they show up
Invasive. Low aggression within the supercolony, high numbers. They tend honeydew-producing insects on plants — landscape aphids feed your ant problem.
Health and property risk
Household nuisance, ecological displacement of native ants, indirect pest increase on plants via honeydew farming. Not fire-ant medical stings.
Proven control sequence
Work in this order. Skipping inspection or exclusion is why most “treatments” bounce back in a week.
- Bait, do not spray trails. Slow-acting sugar baits in stations along trails. Sprays split nothing useful at supercolony scale and can worsen indoor pressure.
- Dry the foundation. Irrigation overspray is a tap. Fix it.
- Manage honeydew on shrubs. Aphids and scales on the hedge are an ant cafeteria. IPM on the plant matters.
- Exclusion. Door sweeps still help the kitchen even if the yard remains colonized.
Matching tools for these steps can be bought on Amazon. Buy the field kit.
Tools for Argentine ants
Supercolonies share food across irrigated yards. A sidewalk spray is a hobby. Liquid bait plus sanitation has to match a landscape-scale nest.
As an Amazon Associate, Pest Kill earns from qualifying purchases. The EPA label is the law for any pesticide. These links match the sequence on this page — they are not a shopping list instead of identification. Details: advertising disclosure. Browse the full tools catalog.
Labeled product
TERRO T300 liquid ant bait stations
For sweet-feeding household ants that take liquid bait back to the nest. Leave the trail alone while they feed. Not for carpenter ants, fire ants, or Pharaoh ants — wrong biology, wrong bait.
Prevention that actually sticks
- A dry inspection strip at the slab.
- No pet bowls on the patio overnight.
When to hire a licensed professional
HOAs and food facilities in infested California cities. Homeowners can bait correctly and still should not expect zero ants outdoors.
United States and Tier 1 notes
California is the US epicenter. Mediterranean climates globally. Not a Minnesota winter outdoor species. Southern Europe and parts of Australia have their own Linepithema stories.
Common questions
Can I eliminate them from my block?
You can reduce indoor trailing. Eradicating a regional supercolony is not a household project.