__NOTOC__ Woodlice (known locally under many names; see below) are terrestrial crustaceans with a rigid, segmented, calcareous exoskeleton and fourteen jointed limbs. They form the suborder Oniscidea within the order Isopoda, with over 3000 known species.
Woodlice need moisture because they breathe through gills, called pseudotrachea, and so are usually found in damp, dark places, such as under rocks and logs. They are usually nocturnal and are detritivores, feeding mostly on dead plant matter. They should be considered beneficial garden organisms as they recycle nutrients back into the soil. In artificial environments such as greenhouses where it can be very moist, woodlice may become abundant and damage young plants.
In the United Kingdom there are 37 native or naturalised species ranging in colour and in size (3-30 mm) of which only five are common: Oniscus asellus (the common shiny woodlouse), Porcellio scaber (the common rough woodlouse), Philoscia muscorum (the common striped woodlouse), Trichoniscus pusillus (the common pygmy woodlouse) and Armadillidium vulgare (the common pill bug).
They have a shell-like exoskeleton. As the woodlouse grows, it must progressively shed this shell. The moult takes place in two stages. The back half is lost first, followed two or three days later by the front. Some woodlice are able to roll into a ball-like form when threatened by predators, leaving only their armoured back exposed. This ability explains many of the woodlouse's common names.
A female woodlouse will keep fertilised eggs in a patch on the underside of her body until they hatch into small, pink offspring. The mother then appears to "give birth" to her offspring.
Bænkebider | Landasseln | Cloporte | טחבית מצויה | Aselo | ワラジムシ亜科 | Oniscidea
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"Woodlouse".
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