Pill-bug
Guides
Armadillidium nasatum
Nosy Pill Woodlouse
Armadillidium nasatum is a large woodlouse species native to Western Europe, particularly Britain, that has been introduced to North America and other regions. It reaches up to 21 mm in length and is distinguished from congeners by a rectangular protrusion ("nose") at the apex of the head and a rounded tail tip with incurved sides. Unlike some relatives, it does not form a complete ball when enrolled. The species exhibits synanthropic tendencies and prefers drier habitats than most woodlice.
Cubaris
Reclined Pill Woodlice
Cubaris is a genus of woodlice (terrestrial isopods) in the family Armadillidae, established in 1833 with Cubaris murina as the type species. The genus contains more than 100 described species, though it has become a wastebasket taxon with many species placed in it that do not fit the original description. Species in this genus are capable of conglobation (rolling into a ball) and have been widely used in ecotoxicity testing due to their sensitive behavioral responses to soil contaminants. Several Cubaris species, particularly undescribed forms such as "Rubber Ducky," have become popular in the pet trade.
Cylisticus convexus
Curly Woodlouse
Cylisticus convexus, commonly known as the curly woodlouse, is a small terrestrial isopod first described by Charles De Geer in 1778. Native to Europe and Asia, it has been introduced to North Africa, North America, and South America. The species is notable for its ability to conglobate (roll into a ball) while retaining protruding antennae and uropods, and for possessing five pairs of pleopodal lungs—features that distinguish it from similar pillbugs.
Gnorimosphaeroma noblei
Gnorimosphaeroma noblei is a marine isopod in the family Sphaeromatidae, described by Menzies in 1954. It is a small crustacean capable of conglobation (rolling into a ball), a defensive behavior common in pill isopods. The species occurs in the temperate North Pacific region. Like other sphaeromatids, it inhabits marine intertidal and shallow subtidal zones.
Venezillo microphthalmus
Small-eyed Venezillo Pill Woodlouse
Venezillo microphthalmus is a small terrestrial isopod in the family Armadillidae, endemic to California. The species exhibits the characteristic conglobation (pill-forming) behavior typical of its family, rolling into a defensive ball when disturbed. It is considered rare on the mainland and has documented populations on the Channel Islands. The species is believed to be declining in the San Francisco Bay Area due to competition from introduced woodlouse species.
Venezillo parvus
Little Pill Woodlouse
Venezillo parvus is a small terrestrial isopod commonly known as the Little Pill Woodlouse. It belongs to the family Armadillidae, a group characterized by their ability to conglobate (roll into a complete ball). The species has been documented in both North America and Europe, with its native range presumed to be European and North American populations representing introduced populations. It is a detritivore that contributes to decomposition processes in terrestrial ecosystems.
Venezillo pisum
Venezillo pisum is a species of terrestrial isopod in the family Armadillidae, first described by Budde-Lund in 1885. The specific epithet 'pisum' (Latin for 'pea') likely refers to some aspect of its appearance or behavior, though the original description's reasoning is not preserved in available sources. As a member of the Oniscidea (woodlice and pill bugs), it is a detritivore inhabiting moist terrestrial environments. The species has been recorded in North America, though it may represent an introduced population given its original description from European material.