Carpenter ants are among the larger ants found in Texas. There are 18 recorded species of carpenter ants in the state of Texas. The most common indoor species is about 1/4-3/8 inch-long with a black tail (abdomen). It has a reddish-brown head and thorax. Other distinguishing characteristics of these ants include a pinched waist and elbowed antennae.

These ants have a single bump or node between the abdomen and thorax, and an evenly rounded thorax when viewed from the side with a hand lens. Carpenter ant swarmers range in size from 1/4 to 1/2 inches long when mature. These ants will emerge by the hundreds at times when they swarm for mating.