Why in Macbeth does the witches use elements of all these different animals to create?

The witches use elements of different animals in Macbeth to symbolize the chaotic, supernatural forces they represent. By blending different animal parts, they evoke a sense of unnaturalness and malevolence, highlighting their otherworldly nature. This imagery reinforces the theme of the supernatural and sets the tone for the dark events that unfold in the play.