A Porcupines Defense Against It's Own Pricks

Porcupines are the only animal in North America with antibiotics in their skin.

Picture from Animals Town

On the occasion that a porcupine manages to stick itself with one of it's own quills, the antibiotic in it's skin will prevent infection.  Typically the quills lay flat until a porcupine is threatened, then leap to attention to act as a line of defense.