Ants Found in California

Ants are some of the most common insect pests—there are more than 700 ant species in the United States.

Pest control companies receive more calls for ant pest control than almost any other kind of pest control. When you see ants scurrying around in a California house or office, they’re probably from one of the following most common species of ants.

Argentine Ants

(Linepithema humile)

Argentine Ants originate from several countries in South America. They’ve traveled to almost every continent in the world, including the United States. Because of that, they’re listed as one of the world’s 100 worst animal invaders. They’re especially prolific in California, where they’ve been wiping out other ant species and establishing a supercolony of their own. Argentine worker ants are a dull brown color and are about an eighth inch long. They emit a musty odor if they are crushed. These ants love sweets, oils, and the buds of some plants. They love the honeydew excretions of aphids and sometimes protect aphids so they can enjoy one of their favorite delicacies.

Carpenter Ants

(Camponotus species)

Carpenter ants are one of the most common types of household ants in the United States. Carpenter ants are so named because they love to nest in wet wood and excavate it into a nest for their brood. Carpenter worker ants are black or black and red and are a fourth inch to a half inch long. They love to eat sweets, honeydew, and other insects. Their main colonies are usually outside the house in dead trees, firewood piles, tree stumps, or fence posts. Their indoor colonies are usually satellite colonies of the outside colonies and are established in window and door frames, subfloors, and hollow doors.

Thief Ants

(Solenopsis molesta)

Thief ants, or Solenopsis molesta, are so named because they have a habit of nesting close to other ant nests and stealing food and ant larvae from them. Thief ants especially love grease, so in some cases they’re called grease ants. In addition to grease, they love to feed on proteins, dead insects, and even dead rodents. The workers are anywhere from 1/32 to 1/8 inch long. They’re yellowish brown in color. Because of their tiny size, they can sometimes be found in packaged foods. Their nests are often found under rocks, in decaying wood, in wall or cabinet voids, or behind baseboards.

Pharaoh Ants

(Monomorium pharaonis)

Pharaoh ants are tiny—the worker ants are 1/16 inch long. They’re yellow, honey-colored, or orange in color. Pharaoh ants love sweets, fats, proteins, and other insects. They’re very mobile and will move a colony to a new location if they get disturbed or if the colony gets too large. Their colonies tend to be in cracks or crevices, behind walls or baseboards, or inside curtain rods, clothing folds, or insulation. Because they’re so tiny and so comfortable in indoor spaces, they can become a major nuisance in hospitals.

Household ants can be difficult to get rid of. Because they’re so tiny, you never know if you’ve successfully eliminated them or if there are still more nests somewhere in the house. Ants in the yard can cause damage to trees and plants. If the ant population at your house is untamable, it might be time to call ant pest control specialists. They’ll know what to do.