What are Banquo's and Macbeth’s reactions to what the witches have told them?From Act 1, Scene 3 of Macbeth

Concerning Shakespeare's Macbeth, you
can read the basics of the two thane's reactions for yourself in Act 1.3.  Most of what
you need is readily apparent. 

To clarify for you, I'll
explain a detail or two and raise a point you may not notice upon a first or second
reading.

The witches are androgynous, first of all.  They
appear to be women, yet wear beards.  Macbeth and Banquo are, if anything, confused. 
Banquo is not afraid at all.  He doesn't take the weird sisters seriously, and there's
no evidence of his feeling any fear. 

Macbeth, however,
starts, or flinches, recoils, according to Banquo.  This is significant.  Banquo
asks:

Good
sir, why do you start and seem to fear

Things that do sound
so fair?

Macbeth's flinch
demonstrates his reaction to his being called the Thane of Cawdor and the prediction
that he will be king.  To flinch is to withdraw from as if from pain or anticipated
pain, to tense the muscles involuntarily in anticipation of discomfort.  Macbeth
recoils, tenses up, withdraws. 

Since we know that being
named Cawdor and becoming king are not in themselves negatives to Macbeth, other reasons
for his flinching must be present.  A couple of possibilities
exist. 

First, the first genuine thoughts revealed by
Macbeth, delivered when no one else hears, are located in his asides starting in line
130.  In the second aside, Macbeth is already thinking of killing
Duncan:

If
good [the predictions, the witches], why do I yield to that
suggestion

Whose horrid image doth unfix my
hair,

And make my seated heart knock at my
ribs

Against the use of nature?  Present
fears

Are less than horrible
imaginings.

My thought, whose murder yet is but
fantastical,

Shakes so my single state of
man

That function is smothered in
surmise,

And nothing is but what is not [nothing exists in
the present but thoughts about the
future].

First, then, Macbeth
may flinch because he instantly recognizes what it will take for him to be king--killing
the present king.  And he fears doing that, as his later second thoughts reveal in Act
1.7. 

Second, however, is the possibility that Macbeth,
even before his encounter with the witches, has already been thinking of what it would
take for him to be king.  This would explain his instantaneous reaction to the
predictions.  He already knows what his becoming king would
cost. 

In short, Banquo does not take the witches
seriously--not at first and not until the first prediction comes true (Macbeth is named
Thane of Cawdor), and is never afraid of the witches.  If he fears anything, he fears
for Macbeth, that's why he warns Macbeth that evil agents sometimes give a small truth
in order to mislead one into "deepest consequence" (128).  Macbeth is not afraid of the
witches, either.  He is afraid of what will need to be done to make their predictions
come true.