The North American porcupine has a cute face, but it has upward of 30,000 menacing quills covering much of its body. The slow-moving herbivore uses them as a last-resort defense against predators.

Once a North American porcupine quill is embedded in tissue, the barbs make it difficult to remove. Quills with barbs required 0.33 N more force to remove than those without barbs.

Porcupine quills "can strongly grip tissue with minimal depth of penetration, less than half a centimeter is enough and they don't need to bend like staples to achieve secure fixation," Ankrum said.

Quills are loosely held by a porcupine's skin, and so if another creature comes into contact with a porcupine, quills detach easily from the porcupine. Not so for the victim though.

Porcupines have about 30,000 quills and can certainly spare a few if they meet a dog. How to prevent this disaster is to keep your dog inside or on a leash at night. That’s when porcupines roam.

Porcupine quills inspire new medical innovations By Ben Coxworth December 11, 2012 Quills may be good for more than just protecting porcupines (Photo: Shutterstock) View 2 Images ...

Porcupines are slow-moving creatures that lack the speed to run away from predators. Instead, defence comes in the form of some 30,000 quills that cover the back of each animal.

The North American porcupine (Erethizon dorsatum) has about 30,000 defensive quills, which are actually stiff hair with a black, cone-shaped tip. Each come with a layer of microscopic, backward ...

Porcupine Quills Can Kill Researchers in Italy watched porcupines corner a dog and stab it to death Colin Schultz November 11, 2013 ...

A poor rescue pup lost his eye when he got 1,500 quills in his face after trying to eat a porcupine. Brutus the Staffordshire ...

Quills are modified hairs covered with scales that are compared to fish hook barbs, meaning they move further inwards. According to VCA Hospitals, porcupine quills can puncture the skin and move ...