Clambus armadillo (De Geer, 1774)

This is a mostly central and northern European species; it occurs from lowland to lower mountain altitudes from France, Italy and northern parts of the Balkans north to the UK and above the Arctic Circle in Scandinavia, to the east it extends into Ukraine and western parts of Russia but is absent from Asia Minor and North Africa, following introductions it has become established in several northern regions of the United States and has more recently become established around Nova Scotia. In the UK it is locally common across southeast and central England and Wales, very local and generally scarce further north into central Scotland and in southwest Ireland.  Adults occur year-round and are common through the spring and summer, they usually associated with decaying vegetation in wetland or permanently damp situations, often among litter and decaying plant debris or among moss etc, while in Northern Europe they are more eurytopic, occurring on open grassland, scrub and bogs, they are frequent among decaying litter in both broadleaf and conifer forests and may be quick to colonize freshly planted areas. Little is known of the biology but both larvae and adults are thought to be mycophagous. Sampling these tiny beetles can be difficult; sieving likely material over a sheet is probably the best method in the field as they can be nimble and are easily seen as they run, but they can also curl up and remain still for long periods and so are very difficult to spot, they very occasionally appear when sweeping marginal vegetation or long grass in hot weather but taking samples of deep decaying vegetation for extraction will often produce the species at any time of year.