For the poor wren,
The most diminutive of birds, will fight,
Her young ones in her nest, against the owl.
– William Shakespeare
Macbeth, Act 4, Scene 2. Lady Macduff criticizes her husband for fleeing to England. She accuses him of being a cowardly and neglectful husband and father, pointing out that even the tiny wren will fight an owl to defend her young in the nest.