It is found in Argentina, Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, Paraguay and Uruguay, typically at lower elevations.

It is a small free-tailed bat, with a forearm length of 28.9–32.5 mm (1.14–1.28 in) and a weight of 5–8 g (0.18–0.28 oz); males are larger than females.

Females might be capable of becoming pregnant multiple times per year, unlike some bats which have an annual breeding season.

It roosts in small groups, typically three or fewer, which can be found under tree bark, in rocky outcrops or buildings, or even within holes in fence posts.

It has a variety of internal and external parasites, including nematodes, cestodes, trematodes, mites, ticks, and bat flies.

[5] American zoologist Gerrit Smith Miller Jr. was the first to use its present name combination, placing it in the genus Molossops in 1907.

Genetic analysis suggests that the Molossops species are closely related to those in the genus Cynomops; they are in a clade along with the genera Eumops, Molossus, Promops, Nyctinomops, and Neoplatymops.

Some authors have hypothesized that females may be polyestrous, or capable of becoming pregnant multiple times a year.

[13] The dwarf dog-faced bat is moderately social, typically roosting in small groups of no more than three individuals.

These echolocation characteristics are adapted for differentiating small prey items from background clutter such as vegetation.

Its diet includes beetles, moths, flies, true bugs, Hymenoptera species, and grasshoppers and katydids.

Its ectoparasites (external parasites) include the ticks Ornithodoros hasei and Amblyomma; the mites Chiroptonyssus venezolanus, Spinturnix americanus, Macronyssus, Trombicula, Steatonyssus, and Chiroptonyssus; the bat flies Basilia carteri (Nycteribiidae) and Trichobius jubatus (Streblidae); and true bugs of the genus Hesperoctenes.

[3] The dwarf dog-faced bat is found only in South America, with a wide range encompassing Argentina, Bolivia, Brazil, Colombia, Ecuador, Guyana, Paraguay, Peru, Uruguay, and Venezuela.

Molossops temminckii griseiventer is known from Colombia in the Magdalena River Valley, as well as the Tolima, Meta, and Cundinamarca Departments.

It has been found in a variety of biomes and ecoregions, including the Amazonian lowlands, Cerrado (tropical savanna), Caatinga (dry shrubland), Pantanal (wetlands), Atlantic Forest, Alto Paraná Atlantic forests, and Argentine Espinal.