Staphylinidae
A family of the large group of Brachelytra, the "Rove" or "Cocktail" Beetles. The species of this group agree in having the wing-cases, or elytra, very short, as indicated by the scientific name, which is derived from brachys, short, and elytra, the wing-cases. Their wings are, nevertheless, large, and have, accordingly, to be folded up, and packed away, below the elytra. The hinder end of the bare abdomen is employed to help in this, being turned up to push the wings under their covers; hence, they are often called Cocktail Beetles. The name Rove Beetles refers to their active roving habits. There are many genera in the family Staphylinidae, but they mostly differ too little to be distinguished by anyone save a practised entomologist. Few of them are over 1/2in. in length, though one or two exceed 1in.; many are microscopic in size. They are very often black, but frequently this is varied with yellow, reddish-brown, or rusty-red. These beetles vary greatly in habits. They are very abundant, and are, accordingly, to be met with everywhere. Towards the end of summer, they may be found crawling on the ground or on walls and palings, or on the wing; and the small species are but too familiar from their liability to fly into one's eyes or mouth. Over 200 species are known to occur in Britain. They may often be found in the utmost profusion in the dead bodies of animals, or in decaying remains of plants, both as larvae and in the perfect state. Some of them are among the most efficient allies of gardeners, because of their influence in destroying noxious insects. None of them are injurious to healthy garden produce. The two species figured, viz., Goerius olens, or the "Devil's Coach Horse," and Staphylinus erythropterus give a fair idea of the appearance of the family. The former preys on insects.