Argentine Ants in El Dorado Hills

Argentine ants (Linepithema humile) are a significant pest in El Dorado Hills, known for their aggressive colony expansion and persistent infestations. Originally from South America, they have adapted well to California’s climate, thriving in both urban and natural environments.

Characteristics of Argentine Ants

• Size & Appearance: Small (2.2-2.8mm long), light to dark brown.

• Colony Structure: Unlike other ant species, Argentine ants form massive supercolonies with multiple queens, allowing them to spread rapidly.

• Behavior: They travel in well-defined trails, often found moving along sidewalks, foundations, and trees.

• Diet: Prefer sweet substances but will also eat proteins and fats.

• Nesting Sites: Commonly found in soil, under rocks, mulch, and near moisture sources like leaky pipes or sprinkler systems.

Problems Caused by Argentine Ants

1. Home Invasions:

   • They enter homes in search of food and water, often appearing in kitchens, bathrooms, and pantries.

   • Difficult to control because of their large colony networks.

2. Displacing Native Ants:

   • Argentine ants outcompete and eliminate native ant species, disrupting local ecosystems.

3. Attracting Other Pests:

   • They protect and "farm" honeydew-producing insects like aphids and scale insects, which can harm plants and gardens.

4. Difficult to Eradicate:

   • Their multiple-queen structure means that eliminating part of a colony doesn’t stop the infestation. Instead, they quickly repopulate.

Prevention & Control

1. Seal Entry Points

• Close gaps around doors, windows, and foundation cracks.

• Use weather stripping and caulk to block small openings.

2. Eliminate Food & Water Sources

• Store food in airtight containers.

• Clean up crumbs and spills immediately.

• Fix leaky faucets and pipes to remove moisture sources.

3. Outdoor Management

• Remove standing water and trim vegetation near the home.

• Keep mulch and firewood away from the foundation.

4. Use Baiting Systems

• Ant baits containing slow-acting toxins (such as boric acid) are more effective than sprays, as worker ants carry the poison back to the colony.

• Avoid using repellent sprays, which can cause colonies to split and spread further.

5. Professional Pest Control

• Due to the complexity of Argentine ant infestations, professional pest control services may be needed for long-term elimination.