Are North American Porcupines Pests? (Problems & Solutions)

Porcupines are kind of cute with their beady little eyes and chunky bodies. You may think them harmless as long as you don’t provoke them and get in the way of their quills

But do not be deceived by this slow-moving, solitary, nighttime forager of the forests. The North American porcupine causes a few more headaches for people and our domesticated animals than is commonly known. 

Are North American Porcupines Pests? 

Yes, these large quilled rodents are considered a bit of a nuisance. Their feeding habits cause damage to trees, plants, and property. Because they move around large (25-50acres) territories to seek out food, they occasionally encounter pet dogs or livestock. Your animals then get quilled due to their curiosity, aggressiveness, or just bad luck.

Then again, the damage they cause is not always extensive since they do not move around in huge numbers. Later in this article, we cover ways to prevent porcupine trespassing, how to handle extraction, relocation, and other ways to minimize porcupine troubles.

But first, let’s talk in more detail about the inconveniences porcupines cause.

Do Porcupines Destroy People’s Gardens?

Because they are herbivores, gardens are like a buffet where porcupines can help themselves to their favorites such as woody plants, nuts, root crops and fruits. They eat what is available in terms of vegetation, and so vegetable gardens, flowering plants, succulents, and other ornamental plants are all at risk.

Once they find a suitable place to feed, they tend to return there until they have consumed everything available. So if you fail to notice the initial damage of their nighttime feeding, you can say goodbye to those carrots you were going to bake into a cake!

Will Porcupines Destroy Trees and Shrubs?

Porcupines eat the inside layers of bark and roots. Like other rodents, they are equipped with powerful jaws and ever-growing incisors that can handle tough woody materials.

In the winter months when little plant life is available, they live only on tree bark and can end up eating from just one tree. The large amount of inner bark they eat around the trunk can cause sickness or permanent damage to the tree

Rose bushes, shrubs with berries, and the smooth bark of ornamental plants are also among their top picks. So keep in mind that trees and shrubs inside your property line are not off-limits to the hungry porcupine!

Do Porcupines Dig Holes In Yards?

In the wild, porcupines do dig to build dens and to find food. They have strong clawed front feet that can easily find a way under a fence to get at some tasty vegetables. If they take an interest in your root crops they will certainly make an excavation in your yard.

Porcupines occasionally try to seek shelter under sheds, garages, or other structures where they feel safe. You might find a burrow in your yard marked with droppings and chewed-up pieces of tree bark. 

Can Porcupines Damage Buildings?

This prickly rodent is not limited to eating living plant matter. They are also known to chew through wooden structures, wood siding, pressboard, window panes, porch furniture, tree houses, and other fixtures made of wood. 

Why Would A Porcupine Gnaw On Wood?

Porcupines need a balance of sodium and potassium in their body to maintain the healthy functioning of their nerves and muscles. Their spring and summer diet of grass, leaves, and other greens contain significantly more potassium than sodium, so they attempt to bring these minerals back to balance by seeking more salt.

Other herbivores like moose, deer, or snow hare suffer the same sodium deficit, so they also try to find naturally-occurring salt sources.

But if the porcupine cannot find enough naturally-occurring salts from aquatic plants, shed antlers, or bones of dead animals in the forest, they may just wander onto your property and sample your rocking chair! The glue used on plywood has some of the sodium that they crave

Continuously chewing on wood also helps file down their rodent incisors. These are said to grow about 12 inches every year, and so constant grinding on hard materials such as wood helps keep their teeth a manageable length.

Do Porcupines Damage Other Human Property?

Unfortunately for us, it is not just wood glue that serves as an alternative salt source for the quilled rodent. Human perspiration and other salts make a few other items porcupine targets.

Do They Feed on Boat Oars And Other Outdoor Equipment?

Boat oars, wheelbarrow handles and other wooden tool handles commonly used for outdoor activities are not just flavored with wood glue, they also absorb salty human sweat. The sodium-depleted porcupine will help itself to this equipment too if they are left outdoors and accessible.

Do Porcupines Eat Leather Gloves and Other Personal Effects? 

Leather items such as saddles, gloves, horse harnesses, and boots come from an animal hide that has undergone a process called tanning. Salts are used in this process and absorbed in the leather product.

These materials are also in frequent contact with human skin (or horse skin!) and so absorb sweat too. No wonder they are like salt licks to the porcupine.

Do Porcupines Damage Cars?

Porcupines are rather notorious for damaging cars. They find their sodium from the undercarriage of cars that are exposed to the roadways.

Will Porcupines Chew On Tires?

Deicing salts are spread out on roads to prevent the formation of slippery ice during the wintertime. These salts are a great temptation for the porcupine, in fact, a lot of them get into vehicular accidents because they venture out on the roadways to lick the road salts. 

These deicing salts also accumulate on vehicle tires as they pass the salty roads, and so the porcupines love to chew and eat these tires too. Their appetite for salty vehicle tires is hearty enough that some hiking trails even leave instructions about how to porcupine-proof your car.

Do Porcupines Eat Brake Lines? (Why?)

All other vehicle parts exposed to road salts become fair game. Perhaps also because of the scarcity of food during winter, these salty and mineral-laden car parts become very appealing. Fuel lines and radiator hoses apparently have also become part of the porcupine menu.

Can Porcupines Be Dangerous To People?

It is difficult to find statistics on North American porcupine injuries to humans. Hopefully, this means people are smart enough to leave them alone in a chance encounter. 

The porcupine is a laid-back plant-eater that doesn’t want trouble with anyone. They are not territorial and rarely even fight with their own kind, except during mating season once a year.

They are usually just looking for the next meal, and on the lookout to defend themselves with their quilled behinds if they feel threatened. 

However, because of expanding human settlements, we do tend to cross paths. The porcupine is a near-sighted creature that may not notice humans and their domesticated animals already nearby while they continue to forage.

If you do get quilled by accident, it will be painful, but can be remedied with medical help. Read on to learn about how the porcupine quills work.

Can Porcupines Be Dangerous To Pets and Other Domestic Animals?

Quill injuries to pet dogs are fairly common, especially during spring to fall when porcupine activity levels are higher. Dogs tend to go after them, whether in their home territory or not and are rewarded with a face full of quills

The quills are not poisonous, and in fact, they have mild antibiotic properties that keep the porcupine itself safe when it accidentally quills itself. However, the spines have a series of backward-facing barbs so they are not easy to pull out.

The quills expand and work their way deeper into the flesh of the unlucky animal as they absorb moisture and the dog scratches or moves around.

This ability of a quill to migrate into the body of its victim is the biggest source of danger, as they might approach and puncture vital organs such as the brain, heart, or lungs.

Apparently, even years after a quilling, a dog can still be in danger of vital organ damage by a stray quill that is overlooked and continues to work its way deeper over time. 

Strangely enough, dogs do not seem to remember their painful quilling lesson, and when they encounter a porcupine another time, will again risk being aggressive!

Curiosity quills the cats and livestock like cows too. Cattle can attempt to nuzzle the waddling porcupine and get a noseful of spikes. 

Extracting the quills as soon as possible is the best remedy. Professional veterinary attention would be the best, so they can sedate, give other medication, and ensure thorough removal of all quills.

Do Porcupines Carry Contagious Diseases?

There was a recent finding about a fungal disease that can really weaken and even be fatal for porcupines. The same parasite is found in dogs, cats, mice, livestock, and humans but does not seem to cause as much harm. There are no reports of porcupine to human spread of this infection.

Since they are mammals they do have the risk of contracting rabies, but this is rare in larger rodents. Other than these, there are no other known porcupine diseases that can be passed on to humans.

How Can You Repel Porcupines From Your Property?

If you have a thriving garden, wood house exteriors, and curious pets in areas where porcupines are known to roam, it is best to plan how to keep them out of your property. 

Secure Your Property So Porcupines Can’t Come In

Fencing is a basic way to protect your property. The fence should be at least 1 to 1.5 feet deep underground to discourage digging, and about 2 feet high. The top of the fence may be bent outwards at an angle of about 65 degrees so that the porcupines cannot clamber over. Electric fencing can also be put at the top.

If you have particular trees that you want to protect, you can surround the bottom with wire mesh or aluminum flashing about 2.5 feet high.

Can You Repel Porcupines With Smells?

There are no conclusive studies on what substances effectively repel porcupines. People have been using DIY remedies to keep these wood chewers at bay and minimize damage. Many of these are strong odor or taste-based repellents.

Will Ammonia, Vinegar, Bleach, or Other Strong Smells Scare Off Porcupines?

The odor of predator urine, which has a similar smell to ammonia, is widely believed to deter trespassing porcupines. Porcupines have a strong sense of smell, and they should be wary of bobcats, owls, coyotes, and fishers which are known threats to their species.

A 1998 study showed a promising repellent effect from predator-associated scents. Porcupines totally avoided test branches on which these odors were applied.

There are commercially available predator urine repellants on the market, although the effectivity may be up for testing in individual situations.

Vinegar, bleach, and other strong smells may repel some rodents and other animals like cats or deer. Mothballs have a very strong odor too but are not recommended for use outside of controlled spaces as is stated in their directions for use. These are toxic to humans and other animals. 

Can You Repel Porcupines With Garlic, Hot Peppers, or Other Natural Remedies?

Substances that leave a burning and stinging sensation are reported to repel not just porcupines, but other mammals like deer, gophers, and beavers as well. The capsaicin in peppers can be very painful irritants to the eyes, nose, and mouth. 

Garlic oil and Thiram (a very bitter substance) were not as successful in preventing porcupines from chowing down on test branches according to the previously mentioned 1998 study.

Can You Scare Off A Porcupine With Lighting or Sound?

Since porcupines are shy nighttime creatures, sudden flashing of light and unexpected sounds may surprise and scare them off. There are a number of repellent devices (link to amazon) available on the market that flash light and emit ultrasonic sound, advertised to drive off various wildlife including rodents and porcupines.

However, as with many of the listed repellent substances and tactics here, the porcupines may actually get used to the smells, sounds, and lights. They will learn, for example, to avoid spots where you put capsaicin and instead treat themselves to safe plants. They can learn to ignore the ultrasonic sound and lights too and will continue to move around and reinvade spaces where they have been flushed out.

So varying combinations of your repellents, the addition of fencing and trapping and relocating may be your best protection from these prickly trespassers.

Can You Use Dogs or Other Pets To Repel Porcupines?

To a certain extent, the odor and noise of a dog would let a porcupine know it should steer clear of a particular yard. However, it is not advisable to rely on your pets to drive porcupines away. Knowing the tendency of our pets to charge, sniff or nudge the quilled rodent, the chances of needing an emergency vet visit is probably not worth it!

Can You Trap A Porcupine And Relocate It?

This is a good alternative for porcupines that have gotten too comfortable entering or living near human spaces. Just remember to inquire with local government offices to make sure you follow the laws and secure permits for trapping and handling this wildlife.

What Kind Of Trap Is Good For Porcupines?

Wire or box traps are suitable, with minimum dimensions of 32x12x10 inches and a spring-loaded door. These can be purchased from gardening and hardware stores. Make sure the trap can handle an animal weighing up to 35 or 40 lbs! 

Put a tasty porcupine treat inside (salt, peanut butter, fruit) and place the trap near the opening of its den or at the area where it has been regularly feeding. Wear gloves as you set the trap up to avoid putting your scent on it.

How Do You Handle A Trapped Porcupine?

Porcupines are not particularly aggressive or quick even when trapped, so that makes it a bit easier. Just remember to be careful about the quills! Wrap the cage with a thick tarp and wear heavy-duty kevlar or canvas gloves and protective clothing when transporting it.

How Far Away Should You Release A Trapped Porcupine?

The recommendation is to release it 10 to 20 miles away (some say even up to 30 miles), in a wooded area far from human settlements or agricultural land. You may check with local officials if there are designated areas for releasing trapped porcupines.

Will Fish and Game Relocate A Porcupine For You?

It is best to check with the local municipality or state authorities charged with managing wildlife what assistance they can give for the relocation of porcupines.

Can You Get Rid of Porcupines By Blocking The Entrance To Its Den?

That would be one way of discouraging it from roaming your property, but it will likely not be very effective

First of all, you have to find a way to completely block the entry of an animal that can dig, and you will have to do this at night when the porcupine has come out to forage. Secondly, the porcupine is probably used to humans being nearby, has found nice food sources in the vicinity, and is fairly comfortable. So it is likely to stick around.

Speak to professionals in your local wildlife and animal control organizations about your specific situation and the help needed.

Author: Eleanor Tan

Eleanor grew up with rottweilers and pit bulls and loved the James Herriot books about animals as a kid. She thinks animals are endlessly fascinating, and that we can learn a lot from them, all creatures, great and small.

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