In Macbeth, the eyes of what animals were used in the Witches' cauldron?

In Macbeth, the eyes of newts were used in the witches' cauldron. The use of newts' eyes in the cauldron can be attributed to the belief in witchcraft during Shakespeare's time. Newts were often associated with magic and witchcraft, and their eyes were believed to possess mystical powers. Therefore, incorporating the eyes of newts into the cauldron added an element of supernaturalism to the witches' concoction, enhancing the eerie atmosphere and emphasizing the supernatural nature of their activities.