The genus Octostruma is known only from the New World tropics, from southern Mexico and the West Indies to northern Argentina (Brown and Kempf 1960). It is a part of the "cryptobiotic" fauna: small, slow-moving ants that live in rotten wood and leaf litter. The very similar genus Eurhopalothrix is known to be predaceous on small, soft-bodied arthropods (Brown and Kempf 1960, Wilson 1956, Wilson and Brown 1985).

Workers and nests are extremely difficult to see in the field. Some species camouflage themselves with layers of soil (Hoelldobler and Wilson 1986). As a result of their cryptic nature, they were considered extremely rare until the 1960's. But increasing use of Winkler and Berlese sampling has shown Octostruma to be relatively common. I encounter them in most Winkler samples from wet forest sites in Costa Rica.

This species appears to favor open, lowland habitats. It follows a pattern in which "amphitropical" species (those with range disjunctions, abundant in Central America and southern South America, but absent or uncommon in Amazonia) favor open or dry-forest habitats. I have collected the species in Winkler samples from Santa Rosa National Park, Finca La Pacifica, Carara Biological Reserve, and Manuel Antonio National Park. At La Selva Biological Station it appears rare, but has been collected in Project ALAS Berlese samples from one second growth forest site, and I collected an alate queen in the lab clearing.