Ant control: identifying the species before treating

By Sandra Liu, IPM specialist, 14 years · 2026-03-22

Ant treatment without species ID is the #1 reason pest contracts fail. Carpenter ants need different chemistry than fire ants need different chemistry than pavement ants. Killing scouts you see doesn't kill the colony — and finding the colony depends entirely on which species you're dealing with.

Carpenter ants: hollow wood = nest

Large black ants (1/4 to 1/2 inch). Indicate moisture damage and often nest in compromised wood. Treatment requires finding and treating the nest, not just baiting the foragers. Cost: $200–$500 for a full treatment. Address moisture source or they return.

Fire ants: visible mounds + painful sting

Reddish-brown, aggressive, build dome mounds in lawns. Endemic to southern half of U.S. Treatment is two-step: broadcast bait (Amdro or similar) for the colony, mound treatment for active mounds. Annual yard maintenance approach: $200–$500/yr.

Pavement ants: small, sidewalk cracks

Tiny brown-black ants under driveways and patios. Generally not harmful but become nuisance indoor. Gel baits work well and are cheap; many homeowners handle these DIY successfully. Pro visit: $150–$300.

Sugar ants / odorous house ants: kitchen invaders

Sweet-attracted; small dark ants forming trails to food. Often emerge in spring. Spraying the trail is the wrong move (kills foragers, scatters colony). Use sugar-based gel baits along trails; let foragers carry it back to the queen. Pro: $150–$300.

Argentine ants: massive supercolonies

Coastal CA, Gulf states. Extremely difficult; supercolonies span properties. Requires perimeter chemistry + baiting + neighbor coordination. Pro pricing higher: $300–$700; expect long-term contracts.