I am not sure, but here is what wikipedia.org says about hedgehog
behavior

Behaviour
A defense that all species of hedgehogs possess is the ability to roll
into a tight ball, causing all of the spines to point outwards.
However, its effectiveness depends on the number of spines, and since
some of the desert hedgehogs evolved to carry less weight, they are
much more likely to try to run away and sometimes even attack the
intruder, trying to ram into him with their needles, leaving rolling as
a last resort. This results in a different number of predators for
different species: while forest hedgehogs have relatively few,
primarily birds (especially owls) and ferrets, smaller species like
long-eared hedgehogs are preyed on by foxes, wolves and mongooses.

All hedgehogs are primarily nocturnal, although different species can
be more or less likely to come out in the daytime. The hedgehog sleeps
for a large portion of the daytime either under cover of bush or grass
or rock or in a hole in the ground. Again, different species can have
slightly different habits, but in general hedgehogs dig out dens for
shelter. All wild hedgehogs can hibernate, although not all do;
hibernation depends on temperature, abundance of food and species.
Hedgehogs are fairly vocal, and communicate not only in a series of
grunts and snuffles, but sometimes in loud squeals (depending on
species).

Hedgehogs occasionally perform a ritual called 'anointing'. When the
animal comes across a new scent, it will lick and bite the source and
then form a scented froth in its mouth and paste it on its spines with
its tongue. This camouflages the hedgehog with the new scent of the
area and provides a possible poison or source of infection to any
predator that gets poked by their spines.

--- In thewoodyallenadorers@yahoogroups.com, "clueless_back"
<joinwaste@...> wrote:
>
> i watched it for the second time yesterday. it's now one of my
favorite
> allen films along with a couple others.
> here's the question: when sally(judy davis) talks about why she
> couldn't reach orgasm while having sex with michael(liam neeson), she
> says something to the effect of "my mind gets hyperactive, i was
> thinking how michael was different from jack(sydney pollack)..." and
> she goes on about how michael is like a hedgehog whereas jack's a fox.
> she then starts thinking about everyone she knows and which are
> hedgehogs and which are foxes. (judy(mia farrow)'s a fox and gabe
(woody
> allen)'s a hedgehog.)
> i think they each represent a certain personality trait, but i'm not
> sure what they are. so help.
>