 Non @-@ bluffing ( aposematic ) displays occur in mammals which possess powerful defences such as spines or stink glands , and which habitually warn off potential predators rather than attempting escape by running . The lowland streaked tenrec ( Hemicentetes semispinosus ) raises the spines on its head and back when confronted by a predator , and moves its head up and down . Porcupines such as Erethizon erect their long sharp quills and adopt a hunched , head @-@ down posture when a predator is nearby . The spotted skunk ( Spilogale putorius ) balances on its front legs , its body raised vertically with its bold pelage pattern conspicuously displayed , and its tail ( near the scent glands ) raised and spread out . 
