Some examples are when you think you see an animal shape in a cloud, or the man in the moon, or when you think you're hearing hidden messages in music.
Wikipedia says pareidolia is "the visual form of apophenia, which is the perception of patterns within random data. Combined with apophenia and hierophany (manifestation of the sacred), pareidolia may have helped ancient societies organize chaos and make the world intelligible."
Another example of course is seeing a face or a pyramid on Mars.
|A satellite photo of a mesa in Cydonia, often called the Face on Mars. Later imagery from other angles did not show the illusion.|