In "Romeo and Juliet", what bird does Juliet try to convince Romeo that they heard? Why?
A nightingale. She knows that once it is morning Romeo will have to go, so she tries to buy more time by convincing him it is still night.
"Wilt thou be gone? it is not yet near day:
It was the nightingale, and not the lark,
That pierced the fearful hollow of thine ear;
Nightly she sings on yon pomegranate-tree:
Believe me, love, it was the nightingale." (III,5,2098)
This desperate little blip of dialogue shows that Juliet really just wants him to stay with her. She knows that come morning, he will have to be gone in order to serve his sentence of banishment. She speaks (most likely) humorously and lovingly to show that she really doesn't want him to go.