Ants can be a challenge to identify without the proper equipment and experience. In many cases, the best way to confirm the identity of an ant is to enlist the help of a pest management professional. Nevertheless, it is possible to identify some of the most common species of household ants without a microscope.
The following pictures and descriptions can be used to help you identify some of the most common Texas ant species. Once you know the species of ant in your home, you can determine where it is likely to nest, what kind of damage it causes, and what kind of control measures are most effective.
Characters used to identify ants
Before you can identify an ant, you should familiarize yourself with a few key things to look for. Before, or while, you collect an ant to identify, look around the area for other similar ants. All ants live in colonies and rarely travel alone. They can usually be seen hunting as a colony for food along well-established foraging trails. When you see an ant trail, observe whether the different workers on the trail vary in size, or whether they are all identical in size. If you can follow the ant trail back to the nest, observe the nest itself. Also, take note of when the ants are active–are they active mostly during the day, or are they most active at night.
If you are still unsure of the ant species after observing them in action, collect a few to examine under a hand lens, magnifier, or microscope, if you have one. The easiest way to capture and kill ants for examination is to fill a small vial, pill container, or jar with a small amount of ethanol or rubbing alcohol. Use the end of a soft cloth, or a brush, wet with alcohol to pick up the ants and drop them in your container. The alcohol will kill your ants quickly and allow you to examine them more closely.
Ants, like all insects, have three main body regions. Unlike many other insects, however, ant body regions are very distinct, with obvious constrictions between the head and thorax, and thorax and abdomen (or gaster)(see drawing). Most ants also have antennae with a long first segment that creates a bend, or “elbow” in the middle of the antennae. Although worker ants, the most abundant members of the ant colony, are wingless, the reproductive caste in the ant colony may have wings. One or more times a year, these reproductive ants may fly from the nest (swarming) as part of the mating process. Termites, also social insects, also swarm periodically in structures; however, the distinct waist and elbowed antennae are reliable characters for distinguishing ants from termites.
Ants have one or two connecting segments between the abdomen and gaster. These segments are called pedicels, or nodes. Because some wasps resemble ants, the presence of these pedicels can distinguish ants from wasps. Wasps may have narrow, even elongated, waists but they lack the distinct nodes characteristic of ants.
Additional useful body characters of ants to include a characteristic smell when crushed, the or absence of a sting, and presence or absence of spines on the head and thorax.
Ant nests may be conspicuous or their nests may be hidden, or inconspicuous. Soil nests may have a distinctive appearance, or they may simply assume the shape of their hiding place under rocks or other objects. When you find an ant nest in the soil, see whether it has a distinctive shape or pattern. Also look for the number and placement of nest entrances. Some ants nest in trees, either making their own cavities or (more commonly) taking advantage of existing cavities from rot or termite activity. Such ants, like carpenter and acrobat ants, may occasionally use your home as a substitute for a nest in a tree or other plant.