The genus has a nearly cosmopolitan distribution with species inhabiting a wide array of habitats in almost all geographic regions.

[3][4] Wheeler (1936) raised Nylanderia to genus, where it remained until Brown (1973) provisionally placed it as a junior synonym of Paratrechina, a status which was later confirmed by Trager (1984).

[8][11] Cladogram of the Prenolepis genus-group based on LaPolla, Brady & Shattuck (2010) and LaPolla, Kallal & Brady (2012):[11][12][a] Zatania Paraparatrechina Nylanderia Pseudolasius Euprenolepis Paratrechina Nylanderia is a large, ecologically important ant genus with a nearly cosmopolitan distribution.

For example, Ward (2000) found that Nylanderia (recorded as Paratrechina) was the fifth-most frequently encountered ant genus in leaf-litter samples from around the world.

Several other species in the genus have also been reported as introduced outside their native range, including N. clandestina, N. flavipes, N. fulva (Rasberry crazy), N. guatemalensis, and N.

Most are conspicuous, epigaeic (living or foraging primarily above ground) generalist species that form large, polydomous nests.

The small (125–150 individuals) colonies of N. faisonensis also inhabit ephemeral locations in the leaf litter or soil of hardwood forests.

[16][17] Nylanderia ants are small to medium-sized (generally between 1 and 4 mm in total length) and range in color from pale yellow to black.

[18] The main features used to distinguish Nylanderia queens from other Prenolepis genus-group genera come primarily from the mandibles and scapes.

[19] Males of Nylanderia can be more difficult to distinguish from other Prenolepis genus-group genera because considerable variation occurs in the genitalic structures at the species level for all genera, and features such as mandibular dentition are not useful since dentition is always reduced in males from that observed in workers and queens (usually to one or two teeth).

The scapes can be useful in separating male Nylanderia from some Prenolepis genus-group genera since they possess macrosetae similar to those found in workers and queens, but at reduced numbers.

Separation of the widespread North American Prenolepis imparis from Nylanderia is based on the extremely short scapes (not much longer than the head) that lack macrosetae.