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

Oklahoma State University's insect diagnostic lab has called the red imported fire ant the most dangerous ant in the state. The workers are reddish-brown, and one colony has ants of many different sizes, which is the easiest way to tell them from native ants. Their mound is fluffy, worked soil with no opening on top, and new ones often show up a few days after a heavy rain.

Disturb a mound and dozens to hundreds of workers pour out and climb grass stems. Each ant grips the skin with its jaws and stings several times; Oklahoma State describes an average of seven to eight stings in a circle. Within about a day a white blister forms at each sting, something only fire ant venom causes.

Carpenter ants are the big ones. The most common indoor species is about 1/4 to 3/8 inch long, with a reddish-brown head and middle and a black abdomen, though other species run from yellow to all black. 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 eat wood. They hollow it out to nest, usually in trees, but indoors they use soft or damp spots: window and door frames, hollow doors, wall voids and insulation. Small piles of sawdust-like material pushed out of a hole are a sign a nest is close, and winged carpenter ants inside in late winter or spring usually mean the nest is in the house.

Oklahoma State's diagnostic lab names the odorous house ant as one of the two most common ants inside Oklahoma homes. Workers are small, about 1/8 inch, brown to black and all about the same size. The quickest check is to crush one: it gives off a smell like rotten coconut.

One colony has many queens and splits into many connected nests, so there can be tens of thousands of workers spread around a house. Outside they nest shallow under mulch, rocks and firewood; inside they like warm, damp spots such as wall voids near hot water pipes. They go for sweets, especially the honeydew aphids leave on plants, and mostly ignore greasy food.

The other common indoor ant in Oklahoma, according to Oklahoma State. Little black ants are tiny, black and all one size, with two bumps in the waist where the odorous house ant has one hidden one.

Their small size lets a colony live in very small spaces: cracks in concrete, soil, under logs. From there they forage inside houses for food.

Big, red ants, 1/4 to 1/2 inch long, with a squared-off head and a row of stiff hairs underneath it that they use to carry loads. Their range runs from Kansas and Oklahoma down through west Texas.

You'll know the nest: a bare, cleared circle with one hole in the middle, often around 12 feet across and anywhere from 3 to 35. They gather seeds and dead insects and store them in the nest. They have a powerful sting, and people playing on a lawn near a nest are the ones who usually find out.