Most Pselaphinae are distinctive for their body shape (9.15.1) where the elytra and abdomen appear as an ‘apical section’, which is always distinctly wider than the head and pronotum (Fig. 1.4.1). In a few genera (Fig. 1.4.1, top left), the body is more linear in shape but these groups always have deep pits on the head, pronotum and elytral base, and always have clubbed antennae (Fig.1.4.1). All tarsi possess three segments. Pselaphinae loosely resemble the Scydmaeninae in body outline but the elytra of pselaphines are shorter and do not cover most of the abdomen. Pselaphinae are widely distributed in North America.

A great diversity of pselaphines can be collected in damp, forested microhabitats, and wetlands, especially if the debris is removed, sifted, and processed in a Berlese funnel. They are sometimes collected at lights. Various favoured microhabitats include leaf litter, flood debris, under bark (Fig. 9.15.2), grass clumps, in rotten logs or stumps (9.15.3), treeholes, in Sphagnum, and under stones (Fig. 9.15.4). Many species live occasionally or exclusively in the nests of ants and termites, feeding on the host larvae or engaging in trophallaxis with the host ants themselves (Akre and Hill 1973). All pselaphines are predators; mostly of small arthropods such as springtails and mites but the myrmecophilous and termitophilous species derive nutrients from their host colonies (see above).