Classification: Kingdom: Animal Phylum: Arthropoda Subphylum: Pancrustacea Class: Hexapoda Subclass: Insecta Order: Coleoptera Family: Staphylinidae

Morphology

Beetle insects (Coleoptera) with slender and flattened body in 3 distinct parts (head, thorax, abdomen), elongated abdomen which often ends in small extensions, 3 pairs of legs, 1 pair of antennae, 2 pairs of wings: the fore wings are thick and leathery (called elytra in beetles) and are short, covering a small part of the abdomen for the rove beetles family; the unfolded wings are allowing flight. They have mouthparts of the grinder type. 
Some staphylinids may be large, such as the odorant Staphylin (Ocypus olens) which is 2 cm long while others are much smaller like Paederus riparius measuring a few millimeters long. Staphylin larvae do not look like adults and have elongated bodies with cerci behind the body and 3 pairs of legs.

Life cycle

Staphylinids lay their eggs in the spring in the soil. The larvae will moult 2 to 3 times before becoming a nymph that will turn into an adukt

Diet

Larvae and adults are predators and hunt mainly at night, larvae, eggs, gastropods (snails and slugs), caterpillars and worms.
The smaller species are detritivorous by degrading dead organic matter and feeding on fungi. 

Habitats

Staphylinids live in hedges and gardens and sometimes hide in dead animals and composts.

Functional roles

Staphylinids act as interesting regulators in the ecosystem because they are predators and they recycle the excrement of other invertebrates. Moreover, they are the prey of hedgehogs, rodents and birds.

Did you know?

The european black staphylinid or odorous staphylinid (Ocypus olens nicknamed "the devil") can straighten its abdomen like a scorpion when it is threatened and projects an unpleasant odor through the anus, which has earned its name.