Baby Porcupine

Porcupines' quills, or spines, take on various forms, depending on the species, but all are modified hairs coated with thick plates of keratin, and they are embedded in the skin musculature. Old World porcupines (Hystricidae) have quills embedded in clusters, whereas in New World porcupines (Erethizontidae), single quills are interspersed with bristles, underfur, and hair. Quills are released by contact with them, or they may drop out when the porcupine shakes its body, but cannot be projected at attackers. New quills grow to replace lost ones. From ancient times, it was believed that porcupines could throw their quills at an enemy, but this has long been refuted.
Porcupines occupy a wide range of habitats in tropical and temperate parts of Asia, Southern Europe, Africa, and North and South America. Porcupines live in forests, deserts, rocky outcrops, hillsides and grasslands. Some New World porcupines live in trees, but Old World porcupines stay on the ground. Porcupines can be found on rocky areas up to 3,700 m (12,100 ft) high. Porcupines are nocturnal. Porcupines in search of salt sometimes encroach on human habitats, eating plywood cured with sodium nitrate, certain paints, tool handles, footwear, clothes and other items that have been coated in salty sweat. Porcupines are attracted to roads in areas where rock salt is used to melt ice and snow and are known to gnaw on vehicle tires or wiring coated in road salt. Salt licks placed nearby can prevent porcupines from injuring themselves. Natural sources of salt consumed by porcupines include varieties of salt-rich plants (such as yellow water lily and aquatic liverwort), fresh animal bones, outer tree bark, mud in salt-rich soils, and objects imbued with urine.