How do Lady Macbeths comments about birds in Scene 5 and Banquos comment about birds in Scene 6 reveal each characters thoughts?

Lady Macbeth's comments about the owl screaming signifies to her the unholiness of their actions, as owls were seen as symbols of death and darkness. Banquo's comments about the rooster crowing at the right moment symbolize his suspicion of Macbeth's intentions, as he senses that something is amiss and that Macbeth may have achieved his ambition through foul means.