This mistaken identity is due to morphological and behavioral characteristics they share with carpenter ants; namely polymorphic workers, a smooth convex thoracic profile, and the tendency to excavate wood.

[3] It was finally elevated to the species level by Wheeler (1917) and remained there in a recent taxonomic review by Del Toro et al.

[5][6] The range of elevation of this species also appears to depend on latitude with ants collected from locations in Oregon as low as 7 m and up to 1700 m in California.

They prefer to nest in the crevices of oaks, alders, elms, cottonwoods, and creosote, in soil, underneath bark of dead trees.

[5] After finding no aggression between workers collected from significant distances apart and no territorial boundary, Wang et al. (2010) speculated that L. occidentale colonies are large and polydomous.

[9] Liometopum occidentale form massive foraging trails that extend 60 m or more from the nest, and can even be observed on hot days with temperatures between 24 and 38 °C.