Azteca velox is a common species in a wide variety of habitats. It occurs most abundantly in seasonally dry areas, synanthropic habitats, and beach margins. Workers are common diurnal surface foragers. They are generalized scavengers and frequently visit extrafloral nectaries. The nests are polydomous, dispersed in multiple plant cavities. The cavities can be in live or dead stems. Colonies have also been associated with myrmecophytic orchids: Epidendrum bicornutum in Costa Rica (Forel 1906) and Caularthron bilamellatum in Panama (Fisher 1992). Colonies also develop, to variable extent, carton nests as extensions of nests in plant cavities.

In Santa Rosa National Park, Costa Rica, I observed several colonies. An incipient colony was in the hollow live stems of an understory shrub, Cassia hayesiana (Fabaceae). The total stem length of the occupied space was about 1m, with inner cavity diameter of 0.5-1.0cm. There was one physogastric queen and no other reproductives. At two entrance sites they had built small globular carton dwellings, 2cm across and packed with workers and brood. The section of hollow stem near the queen was entirely plugged with a mass of eggs and young brood. The nest also contained a Microdon (Syrphidae) puparium.

A second incipient colony was in a shaded Cordia alliodora tree, a myrmecophyte usually occupied by Azteca pittieri. A lone physogastric queen was in one of the internodes, and workers and brood were dispersed in other nodes of the tree. Some of the Cordia nodes had small carton nests built on the surface.

In the forest at Santa Rosa I also observed a parabiotic association between Azteca velox and Camponotus atriceps. Workers of Azteca and Camponotus were running in and out of the same fissure in a tree trunk, showing no aggressiveness toward each other.

I observed a colony near Punta Quepos, at the edge of a small patch of degraded forest surrounded by pasture. About 4m of trailside had 10-20cm long carton nests scattered in the vegetation, on larger stems. I scraped one nest into a plastic bag - it contained a very high density of workers but no brood. A dead branch, in contrast, was packed with brood, males, and alate females. The dead branch was 3cm diameter with a 1-1.5cm diameter continuous internal cavity. The ants had constructed rather regular perforated platforms inside the branch, every 1-1.5cm, making the inside look much like a Cecropia branch interior.