Woodlouse
Ligiamorpha
Dubioniscidae
Irmaosidae
Pseudarmadillidae
Scleropactidae
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A
woodlouse, also known as a
pill bug (genus
Armadillidium only),
armadillo bug,
sow bug,
slater,
ball bug, or
rolly polly, is a
terrestrial crustacean 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 and so are usually found in damp, dark places, such as under rocks and logs. They are usually
nocturnal and are
detritivore, feeding only on dead plant matter.
In the
UK there are 37 native or naturalized species ranging in colour and in size (3 to 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).
Some woodlice are able to roll into a ball-like form when threatened, leaving only their armoured back exposed. It is this ability which 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 be "giving birth" to her offspring.
See also
Woodlouse hunter spider
