Active at night, the Philippine porcupine searches for plant material on which to feed (2), when it may be heard making pig-like grunting noises and rattling its quills (3) (5). Details of this species’ diet are not known, but other porcupines in the genus Hystrix have a varied diet, comprising bark, roots, tubers, rhizomes, bulbs, fallen fruits, and cultivated crops. They may also sometimes also feed on insects and small vertebrates, and even carrion (3). Bones have also been found in and around the burrows of these porcupines, which are thought to have been carried there for gnawing, to sharpen teeth and obtain calcium (3).
During the day, the Philippine porcupine may shelter in a burrow that it has dug itself, or in an old abandoned mine (2). Hystrix porcupines typically share the den with a small family group, although the female may establish a separate den in which to bear young. Hystrix porcupines typically give birth to one or two young, after a gestation period of around 100 days (3). The Philippine porcupine has been recorded living to nine years and six months in captivity (3).
While the spines of the Philippine porcupine are thought to play a role in regulating body temperature (5), their alternative purpose of defence is far more impressive to observe. When threatened, the Philippine porcupine may raise its quills to double its apparent size. If threatened further, the porcupine may stamp its feet, rattle its tail, and eventually charge backwards, attempting to drive its thicker, shorter, rear quills into the enemy (3) (5) (6).