The porcupine is a familiar mammal of forests and woodlands, and is most common in treed areas where there are rocky ledges and rock piles suitable for dens. Usually seen munching on bark and needles up high in the trees, it is seldom encountered on the ground. However, when it is, the porcupine not too difficult to approach, being both shortsighted and slow moving. If it feels threatened during such an encounter, it will retreat to the nearest shelter, under a rock or log or up a tree. If no such retreat is available, it will hump its back, pivot on its front feet and turn its back to the enemy. With all the quills erected, the porcupine will stomp its back feet and lash its tail threateningly, causing the quills to come free and fly through the air.

The porcupine is Canada’s second largest rodent, next to the beaver. Adult males reach an average weight of 5.5 kg after six year, while females reach 4.5 kg. They do not hibernate in winter. If feeding in a tree during rain or snow, it will sit hunched in a tree, even during subzero weather, until the rain or snow stops. When the weather is dry in winter it will feed at any time of the day or night, but during the rest of the year it is nocturnal despite the weather.