Types of Ants in North Texas: How to Identify Them and What to Do

Fire ants are active across North Texas. When NBC 5 found them along a Plano trail in the fall of 2015, Texas A&M AgriLife urban entomologist Mike Merchant explained that rain and cooler weather bring colonies that stayed hidden all summer up toward the surface. Workers are reddish-brown and about 1/8 to 1/4 inch long, and one colony has ants of many sizes, which Texas A&M calls a distinguishing trait; many other ants are all one size.

The mound is fluffy, worked soil with no opening on top, because the ants come and go through tunnels underneath, and it is easiest to spot a few days after a heavy rain. Disturb one and dozens to hundreds of workers crawl up anything vertical, biting and stinging again and again. The sting feels like a burn, and a day or so later a white, fluid-filled blister forms at the spot, something only fire ant venom causes.

They almost always nest outdoors, but they come inside for food and water, especially in late summer. In winter, Merchant said, they look for places that hold heat, such as walkways, utility boxes and houses.

The odorous house ant is native and found across the United States, and NBC 5 reported in 2010 that it had begun turning up in Dallas-Fort Worth homes a few years earlier. Workers are brown, about 1/8 inch long and all one size, and the single bump in the waist is hidden from above. The quickest check is to crush one: Texas A&M AgriLife describes a pungent smell like rotten coconut.

A colony holds anywhere from a few hundred to 10,000 ants, usually with several queens, and they move their nests often. Outdoors they nest in soil under stones, logs and mulch; indoors they use wall voids and brick. They are drawn to sweets.

Texas A&M AgriLife calls the pharaoh ant the most commonly occurring indoor ant in Texas, and notes it is sometimes called the sugar ant. It is tiny, about 1/16 to 1/12 inch long, pale yellow to reddish-brown with a darker tip on the abdomen, and it has two bumps in the waist. All the workers are the same size.

Texas A&M says they generally live only in heated buildings, because outside subtropical areas such as southern Texas they can't survive outdoors all year. Indoors they nest in dark, narrow spaces near warmth and water: wall voids, electrical boxes, cardboard boxes. One colony spreads across many nests whose ants move freely between them. They feed on sweets and greasy food, and they don't sting.

Texas A&M AgriLife calls carpenter ants a common sight around Texas homes throughout the year. They are the big ones: the most common indoor species is 1/4 to 3/8 inch long, with a reddish-brown head and middle and a black abdomen, though other Texas species run from yellow to all black, and workers in one colony vary in size. Seen from the side, the top of the middle section is one smooth curve, and there is a single bump in the waist. They don't sting, but they can bite.

They don't eat wood. Texas species prefer to nest in trees and in hollows that already exist, and indoors they use hollow-core doors, window and door frames, wall voids, insulation and cardboard boxes. Small piles of sawdust-like material pushed out of a small hole mean a nest is close, and winged carpenter ants inside in late winter or early spring generally mean the nest is in the house.

Texas A&M AgriLife lists the little black ant among the native ants Texans find, and notes it is a close relative of the pharaoh ant. It is tiny, about 1/16 inch, shiny black and all one size, and it moves slowly. Its trails, from a few ants to hundreds, often run along sidewalks and foundations.

Outside, colonies nest in soil, leaving small craters of fine soil in a lawn, or under rocks, logs, bark, firewood and stacked brick. Inside they use woodwork, wall voids, masonry and the space under carpet, and they raid pantries and food cabinets. A colony has up to about 2,000 workers and many queens. They eat other insects and the honeydew aphids leave on plants, and they prey on young fire ant queens.

The pavement ant takes its name from where it likes to nest: open, well-drained, gravelly soil like the ground under sidewalks and pavement. It came to the U.S. from Europe. Workers run from light brown to black, every worker in a nest is the same size, and up close there are two small bumps in the waist and two small spines on the back of the middle section.

An entomologist writing on Insects in the City, a blog for Texas pest professionals, describes a Dallas-area home with a stubborn fire ant problem whose mounds turned out to belong to pavement ants, and suspects the ant is more common in Texas than people realize because it gets mistaken for fire ants. The giveaway is behavior: disturb the mound and pavement ants are slower and less aggressive than fire ants.

Big, red ants, larger than fire ants, with a row of stiff hairs under the head that they use to carry loads. Most workers are about the same size. Texas A&M gives their range as Kansas and Oklahoma through western Texas into Mexico, and lists them among the native ants Texans find.

You'll know the nest: a bare, cleared circle of coarse soil with one hole in the middle and no mound. Texas A&M puts the cleared area at about 12 feet across on average, anywhere from 3 to 35 feet. They store seeds, scavenge dead insects, and are food for the Texas horned lizard. They have a powerful sting that can be dangerous to sensitive people, and Texas A&M notes that people playing on lawns and in parks near a nest are often the ones who get stung.