[2] The species is now believed to originate in the southeastern United States[6][7] and to be exotic or invasive in southern Canada,[4][6] Europe (France,[6][7] Germany,[6][8] Italy,[9] the Netherlands[10]), South America (Uruguay, Chile),[2][6] and the Bahamas.

[11][6] Eastern subterranean termites, like other social insects, share resources and divide labor based on a caste system.

They are sterile and forage for food and water, construct and repair shelter tubes, feed and groom other termites, care for eggs and young, and participate in colony defense.

[13] Soldier termites are also wingless and resemble workers except that they have a large, rectangular, yellowish-brown head with long black mandibles.

[15][16] Immature termites on the sexual, or reproductive, line are called nymphs and can be distinguished from workers by the presence of wing buds.

In R. flavipes, they are 8.5-10mm in length to the tips of their wings[18] and have compound eyes, ocelli, and a dark brown to black fully sclerotized cuticle.

Female neotenics lay eggs at a lower rate than queens, but when present in large numbers, they may play a significant role in the growth of the colony.

[13] The first person to observe and formally describe symbiotic flagellates in R. flavipes was the American paleontologist Joseph Leidy.

In 1877, he reported his findings to the Academy of Natural Sciences of Philadelphia, describing three new species which he mistakenly took to be parasitic ciliates: Trichonympha agilis, Pyrsonympha vertens, and Dinenympha gracilis.

[21] Prof. LEIDY remarked that in seeking small animals beneath stones and fragments of wood in our forests, observing the very common White Ant, Termes flavipes, he noticed that the intestine of the insect, seen in the translucent abdomen, was distended with brown matter.

Feeling curious to learn the exact nature of this matter, he was surprised to find that it consisted largely of infusorial and other parasites, mingled with minute particles of decayed wood.

The authors question whether P. major, which was first described in Reticulitermes hesperus, is truly found in R. flavipes and consider it a case of mistaken identity.

[26] The flagellates break lignocellulose (xylan or cellulose) down into simple sugars, which they ferment for their own energy needs, producing CO2, H2, and short-chain fatty acids such as acetate as waste products.

[26] Most bacterial species in the termite gut are difficult or impossible to culture,[26][28] so methods like 16S ribosomal RNA sequencing are used to identify which groups are present.

One such analysis of R. flavipes worker guts uncovered representatives of the Endomicrobia (Elusimicrobiota), Actinomycetota, Pseudomonadota, Bacillota, Bacteroidota, and Spirochaetota.

[28] The dominant bacterial taxon in the core gut microbiome is the genus Treponema (Spirochaetota), which accounted for approximately 32% of sequences in another 16S rRNA study.

[29] Artificial defaunation of Reticulitermes species by force-feeding on starch or starvation leads to a loss of flagellates and, by association, these endosymbiotic Endomicrobia, and an increase in abundance of free-living relatives.

[30] A rare free-living member of this class, Endomicrobium proavitum, the first Endomicrobia species to be cultured and named, was isolated from sterile-filtered gut homogenates from defaunated (starch-fed) R. flavipes workers.

[38] These two species are believed to be the dominant methanogens in R. flavipes and are found in the peripheral, microxic region of the hindgut, on or in close proximity to the gut wall, where they are sometimes attached to filamentous prokaryotes.

[39] Termites feed on wood cellulose, meaning that their presence in human made structures often goes unnoticed for lengthy periods of time.

The Eastern subterranean termite is considered a serious economic timber pest and it is estimated that in high activity areas more than 1 in 5 homes have been or will be attacked.