How to Get Rid of Ants in Your House (2026 Guide)

Argentine ants (Linepithema humile) are the dominant ant species throughout Greater Los Angeles and most of Southern California — and they behave in ways that make standard pest control approaches ineffective.

Most ant species in the US form isolated colonies with a single queen. Kill the queen and the colony collapses. Argentine ants operate as a supercolony — a genetically related network of multiple nesting sites with thousands of queens spread across potentially hundreds of meters of territory. Two Argentine ant workers from opposite sides of a neighborhood will not fight each other; they are cooperating members of the same supercolony.

When you spray visible ant trails with a repellent product, you kill foragers but the colony simply reroutes around the treated area within hours. The supercolony detects the repellent chemical and avoids it — this is called 'budding' when it causes the colony to split and spread further. Standard kill-on-contact sprays are counterproductive for Argentine ant control.

Effective Argentine ant control requires:

1. Slow-acting bait that foraging workers collect and carry back to all queens
2. Non-repellent exterior perimeter treatment that creates no-go zones without triggering budding
3. Multiple treatment visits over 4–6 weeks as the colony declines

For other ant species present in LA (carpenter ants, fire ants, pavement ants), different approaches apply.

Before treating, identify which ant you have:

Argentine Ants — Small (1/16 to 1/8 inch), light to dark brown, no stinger. Move in distinct trails, often along edges of walls, baseboards, tree branches, or pavement. The dominant species in most LA residential areas.

Carpenter Ants — Large (1/4 to 1/2 inch), black or black and red, sometimes winged. Found near moisture-damaged wood — window frames, decks, wood in contact with soil. Do not eat wood; excavate it to nest. If you see large black ants near your home structure, this warrants inspection.

Fire Ants — Reddish-brown, 1/8 to 3/8 inch. Aggressive; their stings cause a burning sensation and can cause allergic reactions. Form distinctive sandy mounds. Found primarily in foothill and valley areas of LA — San Fernando Valley, San Gabriel Valley, Santa Clarita area.

Pavement Ants — Small (1/16 inch), dark brown to black. Nest under pavement cracks and sidewalks; enter homes through foundation cracks. Less common in LA than Argentine ants.

Step 1 — Stop using repellent sprays immediately.
Repellent products (most store-bought ant sprays) cause supercolony budding and make the problem worse. Stop using them now.

Step 2 — Eliminate food and water sources.
Argentine ants enter homes primarily for food and water. Wipe up spills immediately, keep food in sealed containers, clean behind appliances, and fix any dripping faucets or pooling water under sinks. Reduce outside watering — ants follow moisture.

Step 3 — Apply slow-acting bait.
The most effective DIY approach for Argentine ants is liquid ant bait stations placed along active trails — not directly on the ants, but near them. The slow-acting bait (Borax-based products like Terro work for light infestations) is collected by foragers and shared with the colony. Do not apply bait near fresh surfaces just treated with any pesticide, as chemical residue repels ants from the bait.

Step 4 — Seal physical entry points.
Caulk cracks around windows, doors, and utility penetrations. Remove tree branches touching the roofline (argentine ants travel along branches).

Step 5 — Call a professional for established infestations.
If you still have significant ant trails after 2–3 weeks of the above steps, the supercolony is too large for retail bait to eliminate. Professional treatment uses higher-concentration slow-acting bait products and non-repellent perimeter treatments that work faster on large colonies. See: Ant Control in Los Angeles.

Carpenter ants require a different approach because they nest in wood, not soil.

First, find the nest. Carpenter ants prefer moist, decayed wood. Check: around leaking plumbing, inside wet windowsills, in wood-to-soil contact points, and in tree stumps or dead trees near the structure.

Address the moisture source. Carpenter ants nest in wood because it is moisture-damaged — fix the leak, replace the rotted wood, and the nesting site becomes less hospitable.

Treat with appropriate products. Residual insecticide dusts applied to void spaces and nest galleries are effective. Gel bait is less effective for carpenter ants than for Argentine ants. A thorough carpenter ant treatment may require drilling into wall voids to reach the nest.

Large or inaccessible carpenter ant infestations require professional treatment.

The most effective ant prevention in Los Angeles is a combination of exclusion, sanitation, and regular perimeter treatment:

• Exclusion: Seal all gaps around windows, doors, and utility penetrations with caulk. Install door sweeps on exterior doors.
• Sanitation: Keep all food in sealed containers. Wipe counters and stovetop after cooking. Do not leave pet food out overnight. Rinse recyclables before placing in recycling bins.
• Landscape management: Trim plants and trees away from the home's foundation and roofline. Argentine ants use vegetation as bridges to enter structures. Keep mulch 6+ inches from the foundation.
• Regular perimeter treatment: Quarterly professional treatment creates a non-repellent perimeter barrier that stops Argentine ant foragers before they enter. This is the most cost-effective long-term solution for LA homes with persistent ant pressure.

Call a professional when: ant trails persist for more than 2 weeks despite DIY baiting; trails reappear in multiple locations throughout the home; you see large black ants (possible carpenter ants) near wood structures; or the infestation is in a commercial kitchen or food preparation area.

LA Pest Pros provides professional ant control across 42 cities in Greater LA using slow-acting bait programs specifically designed for Argentine ant supercolonies. Call (213) 555-0187 for a free estimate. See our ant control service page.

Call (213) 555-0187 — we respond within 15 minutes. LA Pest Pros covers 42 cities across Greater Los Angeles with professional Argentine ant control. Free estimates, upfront pricing.