Paederus is a genus of small beetles of the family Staphylinidae. With 622 valid species assigned by 1987 to the subtribe Paederina, and with all but 148 within Paederus itself, the genus is large. Due to toxins in the hemolymph of some species within this genus, it has given its name to paederus dermatitis, a characteristic skin irritation that occurs if one of the insects is crushed against skin. That name, Paederus dermatitis, is a poor choice because, decades earlier, the affliction had been called dermatitis linearis, a name that works in all languages, not just English, because of its Latin origin; the name Paederus dermatitis is also inappropriate because it has shown to be caused by (a) only a few species of the genus Paederus, but (b) also a few species that belong to closely related genera within the subtribe Paederina. A scholarly paper in 2002 suggested that a Paederus species could have been responsible for some of the ten Plagues of Egypt described in the Bible's Book of Exodus.

The rove beetles are a family (Staphylinidae) of beetles, primarily distinguished by their short elytra that typically leave more than half of their abdominal segments exposed. With over 66,000 species in thousands of genera, the group is the largest family in the beetle order, and one of the largest families of organisms. It is an ancient group, with fossilized rove beetles known from the Triassic, 200 million years ago, and possibly even earlier if the genus Leehermania proves to be a member of this family. They are an ecologically and morphologically diverse group of beetles, and commonly encountered in terrestrial ecosystems.