Biology Reference
In-Depth Information
Porcupine
The quills vary in length; those on the back are the longest, while the shorter ones are located on the
head and tail. The longest quills can span as much as five inches, but most measure about three inches.
The majority of quills are white for much of their length—possibly to make the porcupine's weapons
highly visible and hence more threatening to a prospective predator—but a few are completely black.
Each quill has an extremely sharp tip and is very loosely attached at its base; it hardly takes more than
a touch to embed the sharp point in the flesh of an attacker, whereupon the quill easily departs from its
very tenuous attachment to its owner.
It's widely believed that porcupine quills are equipped with tiny barbs, like those on a fishhook: they
aren't, although for all practical purposes they might as well be. Instead, the tip of a quill has diminutive
scales, much like tiny fish scales. These overlap so that the raised edges point toward the rear and func-
tion in much the same manner as the barbs on a fishhook; once embedded in flesh, these scales make it
very difficult and painful to remove a quill. In any event, to the animal or human painfully stabbed by
a number of these miniature lances, the technical difference between barbs and scales is probably of no
consequence!
Because of the scales, lodged quills tend to work their way forward. There are numerous instances,
in both humans and animals, of quills that have disappeared, worked forward, and, after a period of
time, emerged at a considerable distance from the entry point. Occasionally, quills have been known to
work their way into a vital organ and cause death. This is probably relatively rare, however; a greater
danger is that an animal whose face and mouth are riddled with quills may be unable to hunt or eat
properly, and thus may die of malnutrition.
One myth about porcupine quills stems from the fact that their hard, tough exterior conceals a more
or less hollow interior. The operative term here is “more or less.” Folk wisdom to the contrary, quills
aren't filled with air like a balloon, and hence don't deflate when their posterior end is cut off. Instead,
quills are filled with light, spongy material, and cutting the end of the quill off is no aid to removing it
from a dog or other creature. Indeed, this tactic may even make matters worse, since it leaves less quill
to grip with pliers or forceps, and may splinter the quill as well.
