7.5 to9.5 mm. Uniformly dark brown with reddish legs and antennae. The first two antennal segments are bare but the third is pubescent. The third antennal segment is longer than the first. Wings absent.

Patrobus assimilis is similar but generally slightly smaller. It can be distinguished by the third antennal segment being the same length as the first.

Often found in damp places and in woodland.

February to October.

Widely distributed in southern Britain but more scarce in the north.

Fairly frequent in Leicestershire and Rutland.