The North American porcupine is a giant of the rodent order. They tower over mice and squirrels, and weigh in at an average of about 15 pounds when fully grown. Porcupines are highly intelligent animals with excellent memories, and produce a variety of noises, some of which can be heard over great distances. Because of their tendency to forage on trees, porcupines may be considered by some to be a nuisance. Although they can be a challenge for orchards, managed forests, and back-yard trees, they contribute greatly to ecological stability in our Northwestern forests by creating dead wood habitat, increasing plant species diversity, and providing food for predators.