Ants are social insects that live together in colonies, with one or more queens and hundreds to thousands of worker ants. Scouting worker ants are responsible for foraging for food and water, laying down pheromone trails that an army of worker ants will follow to bring food back to the colony. They typically nest outside but often enter homes. If you see a few ants entering from outside, chances are there are many more using the same trail to enter.
Ants can live for a long time without food but can’t survive even one day without water, so they venture indoors seeking moisture. Seal off ant entry points by caulking around windows, doors and openings where utility pipes enter your home. Seal food in the kitchen, sweep and vacuum often and wipe off countertops after preparing food. Don’t leave pet food or water out continuously and fix leaky pipes and faucets. Outdoors, keep landscaping trimmed several inches away from your foundation.
Harvester ant: This large (1/4 inch to 3/8 inch), sometimes aggressive brown/red variety almost exclusively nests outdoors in large mounds. Harvester ants can sting or bite when disturbed, sometimes causing an allergic reaction. Their feeding trails leave behind a distinctive odor.
Carpenter ant: Large (1/4 inch to 5/8 inch), black or bicolored red/black, carpenter ants build nests in wood and can cause significant structural damage to homes. Carpenter ants generally nest outdoors but enter structures when foraging for food at night. They can also establish satellite nests in moist wood indoors. Some varieties have wings.
Pharaoh ant: This small (1/16 inch), light brown species nests indoors in void spaces and scavenges fats, proteins and sweets. The pharaoh ant can be a challenge to control because conventional treatments can cause the colony to split and relocate elsewhere in your home.
Pavement ant: Dark brown to black with light antennae, the pavement ant’s name comes from its habit of nesting beside and under driveways, sidewalks and foundations outdoors. Although this relatively small ant (3/16 inch). Pavement ants are typically seen outdoors, swarming in the spring. Pavement ants may be seen indoors, but typically during winter months.