Prickly tree dwellers
North American porcupines are tree-dwelling rodents that rarely come to the ground. Their quills serve as a defensive weapon, but despite this protection, they sometimes fall prey to predators such as bobcats, coyotes, cougars and fishers. A female advertises her fertility through smells and sounds. The otherwise solitary and territorial males then come together and fight over the female; biting and stabbing each other, they decide among themselves who gets to mate with the female.