What are some examples of dark imagery in Macbeth?

In William Shakespeare's Macbeth the ambition for power leads to the dark and mysterious realm of witchcraft, murders, insomonia, and madness.  And, the imagery used to inspire the experiences of darkness and evil are abundant.

Certainly, the weather connotes sinister acts. For instance, the play opens with "fog and filthy air" as the three witches stir their cauldron and the captain describes the actions of the dauntless Macbeth:

For brave Macbeth--well he deserves that name--

Disdaining fortune, with his brandished steel,

Which smoked with bloody execution. (1.2.16-19)

And, throughout the play there are storms, dark castles in which the candles are out (2.2,5), and murders in the night. As Lady Macbeth prepares to "unsex" herself in order to encourage Macbeth in his deadly deeds, she asks that heaven not "Peep through the blanket of the dark" (1.53)

Enthralled by the prophecies of the "instruments of darkness" as they win him with "honest trifles," Macbeth spends many a night of "curtained sleep" (2.2.51).

When Macduff and Lennox arrive at Macbeth's castle in Act II, Scene 3,  Lennox describes the night as "unruly," speaking of confusion.  He describes the earth as shaking the livelong night."  Ironically, Macbeth agrees, "'twas a rough night" (2.3.63).

The many dark images of night and its predominance in the play clearly suggest that evil abounds:

That darkness does the face of earth entomb. (2.4.

Banquo says in Act III that he

must become a borrower of the night

For a dark hour or twain.(3.1.27-28)

And, as he sends his murderers to kill Banquo, Macbeth comments,

Good things of day begin to droop and drowse (3.3.53)

In Act IV, Malcolm, determined to return to Scotland tells Macduff, "The night is long that never finds the day" (4.3.240). And, so it is for Macbeth whose many nights of murder have finally caused the madness of Lady Macbeth as well as that of Macbeth himself.