Keep Ants Out of Your House: Identification and Control

Of 400+ North American ant species, only a few are household pests. Pavement ants (dark brown, 1/6-1/8 inch) nest under stones and in concrete cracks. Pharaoh ants (light brown/yellow, same size) nest in walls, under floors, behind baseboards. Odorous house ants (brown-black, smell when crushed) nest near heat or in insulation. All three eat human food, especially sweets.

Carpenter ants (1/4-1 inch, black) nest in damp, dead wood — they don't eat it like termites. Their presence indicates rotting wood. They leave sawdust-like frass.

Fire ants (red, painful sting, mound-builders) damage roots and equipment.

When you see a lone ant, it's a scout. Kill it and wipe its pheromone trail with vinegar-water or household cleaner so others can't follow. Baits like Terro (borax + sugar water) work well — workers carry poison back to the colony. Prevention: store food in airtight containers, keep counters clean, caulk entry points. For pet food, place the bowl in a larger water-filled dish — ants won't swim.