They say that Porcupines taste great. Mountain men and native peoples would target them for dinner. Fossil records suggest that these spiny critters evolved from South America.
The Quill Pig is a nearly 30-pound critter that is always ready for any retaliation. They are armored with over 30,000 sharp and barbed quills. Only their nose and pads of their feet are without quills.
Quills are modified hairs that are up to 5 inches long. They are not venomous and can’t be thrown or launched into a predator. When threatened, the porky displays and spreads their quills that can stick in any direction. The super shar quills stick quickly. Once embedded in the skin, they can also travel throughout the body.
I had a hunting dog named Coalby that would not leave Porcupines alone. She would attack them even if they were dead. One incident was so bad that I had to take her to the vet to remove over 300 quills from her muzzle and face. I removed the quills myself on several other occasions.

My guess is that she could smell the Porcupines. They excrete an odor that smells like exotic cheese, from a gland near their tails. You would think that a couple encounters would deter a dog from attacking these quilled warriors. Not Coalby.
Aside from humans, the only predators that pursue Porcupines are mountain lions and fishers. Other predators pay a prickly price.
Porcupines are vegetarians but seek out wood and salty materials. One of my buddies had his hunting camp chewed up by a family of porcupines. They gnawed on his sheathed siding. Apparently glue that holds plywood together contains plenty of salt. Trees are also a target when the chewing critters feast on the outer bark until the tree dies. Tool handles, machinery, rubber hoses, canoe paddles and oars are all at risk of being eaten by hungry Porkies. Shed antlers are also a calcium laden treat.
Active all year means an encounter is likely. Most movement occurs at night. They are not a protected species in Montana.
Porcupines are on the decline in Montana. Apparently, an unknown rodent disease is to blame. More research needs to be completed.

Spring is a common time to encounter these prickly pigs. Keep your dogs on a leash and back away. If the Porky is in your shed or barn, use a broom to push and sweep the critter away.
Stay away from the prickly porcupines!
Montana Grant