for remaining in place. The quills have inspired research for such applications as the design of hypodermic needles and surgical staples. In contrast to the current design for surgical staples, the porcupine quill and barb design would allow easy and painless insertion, as the staple would stay in the skin using the anchored barb design rather than being bent under the skin like traditional staples. Porcupines are also sometimes kept as an Exotic pet. The porcupine is often used as a symbol of American libertarianism due to its natural embodiment of defensiveness and the non-aggression principle. Habitat Porcupines occupy a small range of habitats in tropical and temperate parts of Asia, Southern Europe, Africa, and North and South America. They live in forests and deserts, rocky outcrops, and hillsides. Some New World porcupines live in trees, but Old World porcupines prefer a rocky environment. Porcupines can be found on rocky areas up to high. They are generally nocturnal but are occasionally active during daylight. Classification Porcupines are distributed into two evolutionarily independent groups within the suborder Hystricomorpha of the Rodentia. Infraorder Hystricognathi Family Hystricidae: Old World porcupines African brush-tailed porcupine, Atherurus africanus Asiatic brush-tailed porcupine, Atherurus macrourus Crested porcupine, Hystrix cristata Cape porcupine, Hystrix africaeaustralis Indian porcupine, Hystrix indicus Malayan porcupine, Hystrix brachyura Himalayan porcupine, Hystrix (brachyura) hodgsoni Sunda porcupine, Hystrix javanica Sumatran porcupine, Hystrix (Thecurus) sumatrae Thick-spined porcupine, Hystrix (Thecurus) crassispinis Philippine porcupine, Hystrix (Thecurus) pumilis Long-tailed porcupine, Trichys fasciculata Parvorder Phiomorpha sensu stricto Family Thryonomyidae: cane rats Family Petromuridae: Dassie rats Family Bathyergidae: African mole-rats Parvorder Caviomorpha Superfamily Erethizontoidea Family Erethizontidae: New World porcupines Brazilian porcupine, Coendou prehensilis Bicolored-spined porcupine, Coendou bicolor Andean porcupine, Coendou quichua Black dwarf (Koopman's) porcupine, Coendou nycthemera (koopmani) Rothschild's porcupine, Coendou rothschildi Santa Marta porcupine, Coendou sanctemartae Mexican hairy dwarf porcupine, Coendou mexicanus Paraguaian hairy dwarf porcupine, Coendou spinosus Bahia porcupine, Coendou insidiosus Brown hairy dwarf porcupine, Coendou vestitus Streaked dwarf porcupine, Coendou ichillus Black-tailed hairy dwarf porcupine, Coendou melanurus Roosmalen's dwarf porcupine, Coendou roosmalenorum Frosted hairy dwarf porcupine, Coendou pruinosus Stump-tailed porcupine, Coendou rufescens North American porcupine, Erethizon dorsatum Bristle-spined porcupine, Chaetomys subspinosus (sometimes considered an echimyid) Superfamily Cavioidea Family Hydrochaeridae: capybara Family Caviidae: Guinea-pigs Family Dasyproctidae: agoutis and acouchis Superfamily Octodontoidea Family Abrocomidae: chinchilla-rats Family Octodontidae: degus Family Ctenomyidae: tuco-tucos Family Echimyidae: spiny rats Family Myocastoridae: nutrias Family Capromyidae: hutias Superfamily Chinchilloidea Family Chinchillidae: chinchillas and allies Family Dinomyidae: pacaranas See