Hedgehogs are small insectivores, looking much like an upside-down oval bowl,
that is covered with sharp quills, which feel much like a bristly brush, with
an adorable little face and ears peeking out from one end.  Neither legs nor
tail are very visible during normal movement.  Hedgehogs roll into a ball of
interlocking spines when threatened, leaving themselves all but invulnerable
to any natural predator.

Hedgehogs do have soft fur on their faces and bellies, and so are not
entirely prickly.  Their spines or quills have no barbs on them, and feel
much like a stiff brush, rather than bunch of needles, unless the hedgehog is
very upset.

Some hedgehogs have what appears to be a narrow reverse Mohawk hairdo (a
narrow furrow that runs lengthwise), though this is not present in all
species (e.g., the Egyptian hedgehog doesn't have this).

    It isn't a scar, they haven't lost quills.  It is natural and helps 
    the quills point forward without getting crossed when they bristle.
    -- Katherine Long

Ranging in size from approximately 4 to 9 inches, or 10 to 22 cm, in length,
mature African Pigmy hedgehogs look for all the world to be little armoured
tanks being led around by one of the busiest noses in the animal kingdom.

Hedgehogs tend to be quite nervous in their temperament, and will generally
duck their head down, accompanied by rapid snuffling or snorting.  This
presents a very prickly forehead to any possible enemies.  The more used to
you (and awake) a hedgehog is, the less they will duck down and snuffle, and
the more their quills will be flat.

The hedgehogs that we keep as pets, throughout North and South America [4.1],
and I believe many other parts of the world, have managed to muddy the
already very clouded waters of hedgehog taxonomy.  What we call ``African
Pigmy'' hedgehogs, are actually a hybrid of a couple of species from northern
and central Africa.  Specifically, they are a combination of the Algerian
(Atelerix algirus) and the White-bellied (A. albiventris).  The Southern
African or Cape hedgehog (A. frontalis) is not really part of the mixture,
although they do seem to be sporatically kept as pets in their native
regions.  The status or categorization of the Pruner's hedgehog (A. pruneri)
is up in the air, and this may actually be an alternate name for the Cape
hedgehog (A. frontalis).

Just to add to the mess, there is more than a little uncertainty which
species actually makes up what we call the long-eared, or Egyptian hedgehog,
in the pet world.  You see, there are Long-eared hedgehogs (Hemiechinus
auritus), and there are Egyptian hedgehogs (not an official name from what I
can tell, most likely these being Ethiopian hedgehogs) (Paraechinus
aethiopicus).  Both of these, as you can tell by their taxonomic names, are
of quite different genera let alone species.

So, as you can see, things are a more than a bit muddled when it comes to
deciding which hedgehog is what.  I must extend my regards to Nigel Reeve,
whose research helped provide some sense of consistency to all of this, at
last.

To add to the fray, here are some comments from Nathan Tenny:

    Hedgehog taxonomy is kind of a mess, and they have multiple Latin names; 
    the leader now seems to be Erinaceus albiventris, but one also sees 
    Atelerix albiventris and Atelerix pruneri.  (I think that Pruner's 
    hedgehog is now considered to be a separate species, but it hasn't 
    always been.)  [this remains pretty uncertain and iffy in most research
    that I've found - ed.]  There may be some overlap with Erinaceus 
    frontalis [Atelerix does seem to have become the accepted genus name
    for A. frontalis - ed.] as well, and just to complicate matters, older 
    works refer to the genus Atelerix as Aethechinus. 

    Grzimek's Animal Encyclopedia says that they weigh about 200-220 grams 
    (about seven ounces); this is for wild animals.  Captives seem to be 
    much larger; the smallest of our three hedgehogs is 250 g and growing, 
    and our large male weighs about 400-450 g when he isn't overweight.  
    (However, all our animals have come from exceptionally large bloodlines.)  
    Adults are about six to eight inches long, depending on how far they're 
    stretching when you measure.

    Hedgehogs are basically nocturnal; they may wake up a couple of times 
    during the day to wander around their enclosures, get a snack or a drink 
    of water, and so on, but they really get active late at night (ours wake 
    up between 10 PM and midnight, but that may be because that's when we 
    turn the lights off).  

    Whether they have wonderful personalities depends on your taste.  Your
    prospective hedgehog will sleep all day, and, while it may well become
    quite sociable when awake, it probably will not let you pick it up when
    it wants to sleep.  (Can you blame it?  More to the point, can you argue
    with it?)  We've never met an African hedgehog that would bite 
    aggressively, though there are rumours of such.  (Note that all the 
    Africans we've known have been not only captive-bred but hand-raised 
    from infancy; we make no guarantees about imports or non-socialized 
    animals.)  They do explore with their mouths, so if you smell 
    interesting, you may get licked or nipped; they have fairly sharp teeth 
    (a row of short pegs with points, but nothing drastic).

As pets go, hedgehogs are generally not cuddly lap-fungus type pets, but if
you want something that's a little different, not too big, and definitely
adorable, then maybe a hedgehog is for you.  If, however, you have been
fascinated by hedgehogs for about twenty years, like I have, there is just no
question.

Among their pros and cons, you should keep in mind the nocturnal nature of
hedgehogs.  If you are a night-owl, or often find yourself up and around
during the dark hours, a hedgehog can be a very welcome companion.  On the
other hand, if you jump out of bed early in the morning and fade with the
sun, you and your hedgehog may never see one another.

Although most hedgehogs rarely, if ever, bite or nip, it does happen, as can
occur with any animal.  For information on biting see section [6.6]

Hedgehogs are also relatively low maintenance (though not ``no
maintenance'').  There's no need to take them out for a walk around the block
in the middle of a raging blizzard, or head off to the park, pooper-scooper
in hand, during a heat wave, with a hedgehog.  Their small, but not too
small, size also makes for a good compromise.  They do prefer regular
attention, but it doesn't need to be long at a time.

Then there's always the one really effective decision factor: hedgehogs are
irresistibly CUTE!