Labia minor is about half the size of Forficula auricularia, at 4–7 millimetres (0.2–0.3 in) long. It is chocolate brown, and less shiny than the chestnut brown F. auricularia. The whole body is covered with fine yellow setae, and the antennae are a paler color. The forceps (pincer) at the animal's tail are used to help unfurl the wings, in preparation for flight. Unlike F. auricularia, Labia minor flies frequently.
Labia minor feeds on decaying plant material and other detritus. In cooler climates, it is only found in warm places, such as actively decaying compost heaps, and are most often encountered when turning the compost. Unusually for an insect, there is extensive maternal care of the eggs and offspring, with the mother feeding them for a week or two after they hatch.